Ein durch Einschreiben eines Bragg-Gitters in eine optische Faser hergestelltes Filter

Tin doped photosensitive glass for optical waveguide

Tin-doped photosensitive optical glass is disclosed, together with applications of the glass in fabricating waveguides and waveguide devices such as Bragg gratings on optical fibres 100. The glass may be coped with phosphorus, boron, germanium, aluminium, gallium, indium, arsenic, antimony, titanium, tantalum, zirconium, niobium, fluorine or lead.

Optical fiber with tin doped core-cladding interface

The present invention concerns an optical fiber 10 comprising a substantially pure silica glass core 12, a concentric tin-doped core/cladding interface region 14, and a concentric fluorine-doped depressed cladding layer 16. The tin-doped core/cladding interface region 14 comprises a low concentration gradient of tin dioxide, which advantageously results in a de minimis refractive index change, resistance to hydrogen incursion, and thermal stability of any fiber Bragg gratings written into the interface region 14.

Optical fibre and optical fibre device

CHIRALES FIBER BRAGG LATTICE

OPTICAL TRANSVERSE ELECTROMAGNETIC WAVE DEVICE WITH FIBER LATTICE AND PROCEDURE FOR THEIR PRODUCTION

Acousto-optic variable attenuator with active cancellation of back reflections

HYDROGEN-RESISTANT OPTICAL FIBER/GRATING STRUCTURE SUITABLE FOR USE IN DOWNHOLE SENSOR APPLICATIONS

A hydrogen-resistant optical fiber particularly well-suitable for downhol e applications comprises a relatively thick pure silica core and a depressed -index cladding layer. Interposed between the depressed-index cladding layer and the core is a relatively thin germanium-doped interface. By maintaining a proper relationship between the pure silica core diameter and the thickne ss of the germanium-doped interface, a majority (preferably, more than 65%) of the propagating signal can be confined within the pure silica core and, t herefore, be protected from hydrogen-induced attenuation problems associated with the presence of germanium (as is common in downhole fiber applications ). The hydrogen-resistant fiber of the present invention can be formed to in clude one or more Bragg gratings within the germanium-doped interface, usefu l for sensing applications.

CHIRAL FIBER LASER APPARATUS AND METHOD

A chiral fiber laser (10) implemented in a fiber Bragg grating mimicking the advantageous optical properties of a cholesteric liquid crystal structure is provided. The dopant, the pitch, the core cross section and dimensions thereof, of the inventive chiral fiber laser (10) as well as the core (14) and cladding (16) materials used in construction thereof, may be advantageously selected and configured to enable the inventive chiral fiber laser (10) to produce lasing at a desirable wavelength. In another embodiment of the inventive chiral fiber laser, a tunable defect is introduced to provide tunable lasing corresponding to the wavelength at the defect mode. Multiple embodiments using coupled fiber optical pumping as well as direct optical pumping for excitation of the inventive chiral fiber laser are provided.

GRATING-TYPE OPTICAL COMPONENT AND METHOD OF MANUFACTURING THE SAME

A grating-type optical component having a high isolation ability at a light-bloc king band and a small clad layer mode combination loss at a signal transmission band, and its manufacturing method are provided. A selected area on a core of an optical fiber is irradiated by ultraviolet beams emitted from an excimer laser source through a phase mask i n order to produce high index of refraction areas and low index of refraction areas arrange d alternately and periodically along the longitudinal axis of the optical fiber. This ultraviolet irradiation is terminated before the index of refraction, which is increasing due to the ultrav iolet irradiation, reaches a target value. Then, the phase mask is removed, and the selected area o f the core is again irradiated by ultraviolet beams, thereby completing the grating-type optic al fiber.

DEPRESSED CLADDING FIBER DESIGN FOR REDUCING COUPLING TO CLADDING MODES IN FIBER GRATINGS

A waveguide, such as an optical fiber waveguide for guiding light waves, which can provide a strongly reflective grating (e.g., a Bragg grating) at a specified wavelength while maintaining very low losses at adjacent wavelengths. The waveguide includes a core, an inner cladding laterally surrounding the core, an outer cladding laterally surrounding the inner cladding, and a grating pattern. The core has a refractive index nco and a first transverse dimension 2A. The inner cladding has a width W and a refractive index nic. The outer cladding has a refractive index noc. The relation between the refractive indexes, nconocnic and 0,5A/(A+W)1, define a narrow depressed well region for limiting cladding losses.

BRAGG GRATING OPTICAL FIBRE SENSOR ASSOCIATED WITH A SCATTERING STRUCTURE AND METHODS FOR LOCATING AND INSTALLING SUCH A SENSOR

PACKAGED OPTICAL FIBER SENSORS FOR HARSH ENVIRONMENT MEASUREMENT SYSTEMS

A fiber sensor (130) package is disclosed. The fiber sensor package includes an interconnection (138) between a first optical fiber (132) and a second optical fiber (136) within a tubing (140) such that the first and second optical fibers are at least partially disposed within that tubing. A bonding material (142) is disposed across an edge of the interconnection around at least a part of the circumferential surfaces of the first and second fibers, holds rigid the interconnection of the first and second optical fibers. The first optical fiber may be a sapphire fiber. The sensor may be used for high temperature measurements in coal gasifiers.

TUNABLE OPTICAL FILTER HAVING LARGE DIAMETER OPTICAL WAVEGUIDE WITH BRAGG GRATING AND WITH REDUCING THE BULK MODULUS

A tunable optical filter has a large diameter cane waveguide (10) with "side-holes" (18) in the cane cross-section that reduce the force required to compress the large diameter optical waveguide without overly compromising the buckling strength thereof. The large diameter optical waveguide (10) has a cross-section of at least about 0.3 millimeters, including at least one inner core, a Bragg (14) grating arranged therein, a cladding surrounding the inner core, and a structural configuration for providing a reduced bulk modulus of compressibility and maintaining the anti-buckling strength of the large diameter optical waveguide. The structural configuration reduces the cross-sectional area of the large diameter optical waveguide. These side holes reduce the amount of glass that needs to be compressed, but retains the large diameter.

OPTICAL WAVEGUIDE GRATING DEVICE AND SENSORS UTILISING THE DEVICE

An optical waveguide grating device comprising a progressive three-layered (PTL) fibre (22), within which a long period grating (LPG) (24) is provided. The LPG's attenuation bands associated with cladding modes up to the 23rdradial mode, particularly cladding modes below mode order (15), are essentially insensitive to changes in the refractive index ns of a surrounding medium, but are sensitive to temperature. Attenuation bands associated with cladding modes greater than 26 have refractive index and temperature dependent sensitivity parameters which are non-zero. By appropriate selection of the cladding modes the device may be used to form a temperature sensor (30) or a refractive index sensor (20). A second grating device (50) comprises two LPGs (56, 58) provided in PTL fibre (52) in a spaced relationship to form an in-line Mach-Zehnder interferometer (60). The second device (50) may also be used to form a temperature or refractive index sensor (70).

Fiber Optic Device for Measuring a Parameter of Interest

An optical fiber (100) utilized as a sensor for measuring a parameter of interest 122 such as temperature, strain, photonic energy intensity, electric field intensity and magnetic field intensity is provided. A first optical cladding layer (104) is disposed on an optically transmissive core (102) that includes one or more optical gratings (114-1). The optical grating(s) (114-1) modifies a propagation path of selected wavelengths of light propagating through the core (102). The optical grating(s) (114-1) also varies the index of refraction of the first optical cladding layer (104). The selected wavelengths of light are determined in part by the index of refraction of the core material 105 as dependent upon a parameter of interest 122 applied to the core material 105 and as varied by the optical grating(s) (114-1). One or more detectors (410, 430, 450, 455) are used for determining the properties of the reflected and/or transmitted light. Knowing the properties of the reflected and/or transmitted ...

Optical waveguide grating and production method therefor

An optical waveguide grating with radiative mode-coupling properties, with exceptional stability and reliability as an optical component, wherein the central wavelength of the rejection band has a low temperature dependence, due to the use of silica glass doped with germanium and boron for the core. The rejection bandwidth can be narrowed without increasing the grating length by forming the radiative mode-coupled optical waveguide grating in an optical waveguide wherein the mean relative refractive index difference of the core is greater than that of optical communication waveguides. The rejection can be increased by reducing the occurrence of cases wherein propagation modes of the core coupled to cladding modes once again couple to the core in palnar optical waveguide gratings formed by making periodic changes in the waveguide structure along the direction of propagation of light in an optical waveguide having a cladding with a lower refractive index than the core surrounding the core, ...

Optical fiber design for secure tap proof transmission

The specification describes optical fibers that are constructed to prevent theft of optical signals. One construction is designed to block access of the core of the fiber to the "writing" radiation necessary to form a grating tap. In this embodiment the optical fiber cladding is provided with a highly absorbing UV layer. In a variation of this embodiment, one or more additional optical paths are provided in the optical fiber to accommodate monitoring signals. The added optical paths allow monitoring signals to be transmitted in the optical fiber, separate from the information signal, to signal an attempt to breach the outer coating or the cladding of the optical fiber.A second case of intrusion is addressed by increasing the sensitivity of the optical fiber to microbending loss to the extent that bends in the fiber cause such high attenuation of the signal that the bends do not go undetected at the receiving station.

FIBER OPTIC SENSOR FOR DETECTING MULTIPLE PARAMETERS IN A HARSH ENVIRONMENT

A fiber optic sensor is provided. The fiber optic sensor includes a fiber core having a plurality of grating elements wherein, the grating elements comprise a periodic or a quasiperiodic modulated microcrystalline and silicon dioxide tetrahedral structure and a cladding disposed about the fiber core.

Optical fiber with tin doped core-cladding interface

The present invention concerns an optical fiber 10 comprising a substantially pure silica glass core 12, a concentric tin-doped core/cladding interface region 14, and a concentric fluorine-doped depressed cladding layer 16. The tin-doped core/cladding interface region 14 comprises a low concentration gradient of tin dioxide, which advantageously results in a de minimis refractive index change, resistance to hydrogen incursion, and thermal stability of any fiber Bragg gratings written into the interface region 14.

Adjustable beam characteristics

Disclosed herein are methods, apparatus, and systems for providing an optical beam delivery system, comprising an optical fiber including a first length of fiber comprising a first RIP formed to enable, at least in part, modification of one or more beam characteristics of an optical beam by a perturbation assembly arranged to modify the one or more beam characteristics, the perturbation assembly coupled to the first length of fiber or integral with the first length of fiber, or a combination thereof and a second length of fiber coupled to the first length of fiber and having a second RIP formed to preserve at least a portion of the one or more beam characteristics of the optical beam modified by the perturbation assembly within one or more first confinement regions. The optical beam delivery system may include an optical system coupled to the second length of fiber including one or more free-space optics configured to receive and transmit an optical beam comprising the modified one or more ...

Optical waveguide grating and production method therefor

Optical connector

The optical connector according to the present invention comprises, at least, an optical filter (12) with a waveguide structure (11) having a grating (126) with a predetermined reflection wavelength and a plug attached to a tip (121) of the optical filter (12). The grating is disposed at a tip portion (121) of the optical filter (12) and accommodated in the plug attached to the tip portion of the optical filter (12). Further, the optical connector has various light-blocking structures for preventing unnecessary light from traveling a filter region (122) of the optical filter (12) including the grating. ...

ОПТИЧЕСКОЕ ВОЛОКНО С ЛЕГИРОВАННОЙ ОЛОВОМ ПЕРЕХОДНОЙ ЧАСТЬЮ МЕЖДУ СЕРДЦЕВИНОЙ И ОБОЛОЧКОЙ

... 1. Оптическое волокно, имеющее ! сердцевину из, по существу, чистого кварца, ! оболочку с уменьшенным показателем преломления, концентрически окружающую упомянутую сердцевину, и ! переходную часть, находящуюся между сердцевиной и оболочкой и включающую фоточувствительную легирующую добавку, содержащую олово. ! 2. Оптическое волокно по п.1, представляющее собой одномодовое или многомодовое оптическое волокно. ! 3. Оптическое волокно по п.1, в котором диаметр сердцевины из, по существу, чистого кварца находится в диапазоне от примерно 3 мкм до примерно 20 мкм. ! 4. Оптическое волокно по п.1, в котором толщина переходной части меньше диаметра сердцевины из, по существу, чистого кварца. ! 5. Оптическое волокно по п.1, в переходной части которого сформирована по меньшей мере одна волоконная решетка Брэгга. ! 6. Оптическое волокно по п.1, в котором фоточувствительная легирующая добавка содержится в концентрации, не превышающей 0,10 молей. ! 7. Оптическое волокно по п.6, в котором концентрация ...

СТОЙКАЯ К ДЕЙСТВИЮ ВОДОРОДА КОНСТРУКЦИЯ ОПТИЧЕСКОГО ВОЛОКНА/РЕШЕТКИ, ПРИГОДНАЯ ДЛЯ ИСПОЛЬЗОВАНИЯ В СКВАЖИННЫХ ДАТЧИКАХ

... 1. Оптическое волокно, стойкое к действию водорода, содержащее ! сердцевину из чистого кварца, имеющую известный показатель преломления и в основном большой диаметр, ! оболочку с уменьшенным показателем преломления, окружающую сердцевину из чистого кварца и включающую легирующую добавку, снижающую показатель преломления, и ! легированную германием переходную часть, расположенную между сердцевиной из чистого кварца и оболочкой и имеющую толщину меньше диаметра этой сердцевины, так что большая часть мощности распространяющегося оптического сигнала заключена в сердцевине и не подвержена действию водорода, диффундирующего в переходную часть, легированную германием. ! 2. Оптическое волокно по п.1, дополнительно содержащее внешнюю оболочку, окружающую упомянутую оболочку с уменьшенным показателем преломления. ! 3. Оптическое волокно по п.1, в котором оболочка с уменьшенным показателем преломления существенно толще переходной части, легированной германием. ! 4. Оптическое волокно по п.1, в котором ...

An optical fibre and method

Chirped optical fibre filter

Chirped optical fibre grating

High index-contrast fiber waveguides and applications

HIGH INDEX-CONTRAST FIBER WAVEGUIDES AND APPLICATIONS

The invention features high index-contrast fiber waveguides (1301) that can be drawn from a preform. The invention also features materials for forming high index-contrast fiber waveguides (1301), and guidelines for their selection. High index-contrast fiber waveguides (1301), which may include opical fibers and photonic crystal fibers, can provide enhanced radial confinement of an optical signal in the fiber waveguide (1301). Moreover, large optical energy densities can be achieved inside the high index-contrast fiber waveguides, making them attractive candidates for a number of applications.

AUTOMATED SYSTEM FOR TRANS-JACKET FIBER BRAGG GRATING INSCRIPTION AND MANUFACTURING

There is provided an alignment system and method for use in an ultrashort pulse duration laser-based Fiber Bragg Grating (FBG) writing system, the alignment system comprising: clamps configured to hold a coated optical fiber in a position perpendicular to a beam path of an ultrashort pulse duration laser-based FBG writing station; an optical detector; and a control system with an input from the optical detector and an output to adjust parameters of an optical source and the FBG writing station adjust a distance between the optical fiber and an optical source of the writing station based on luminescence generated in a core of the optical fiber as indicated in a signal received at the input from the optical detector.

NOVEL MULTIMODE FIBER FOR NARROWBAND BRAGG GRATINGS

A novel multimode fiber structure with modal propagation characteristics tailored to facilitate the creation of narrowband, high reflectivity, fiber Bragg gratings is disclosed. The fiber structure comprises concentric cylindrical shells of higher and lower refractive index material. A full vector, second order finite element method is used to analyze the proposed multimode fiber structure. Simulations of the modal profiles show that high order modes are localized to particular high refractive index shells. We present the theoretical characterization of the modal propagation constant as a function of inner shell radius, shell separation, and harmonic mode parameter. It is shown that a fiber with a minimum inner shell radius of at least 25.lambda. (where .lambda. is the vacuum wavelength), and a minimum shell separation of at least 10.lambda. provides a reasonable trade off between fiber size and grating performance. A simulation of the multimode fiber grating shows that a grating with a ...

FIBER OPTIC DIFFRACTION GRATING

The present invention is directed to an optical fiber grating having a core, that is capable of controlling the light signal transmission therethrough by causing at least one of: at least one spectral peak, and/or at least one spectral dip in its core light transmission spectrum, corresponding to at least one predetermined wavelength. The inventive optical fiber diffraction grating comprises at least one longitudinally positioned structural element of a predetermined geometric profile and that is configured for diffracting a portion of the transmitted light signal at at least one predefined wavelength thereof, from at least one core mode into at least one of: at least one cladding mode and/or at least one radiating mode. Various embodiments of a number of novel techniques for fabrication of the inventive optical fiber diffraction grating are provided, inclusive of a novel technique for fabricating the inventive grating from a single material. Advantageously, such novel fabrication techniques ...

RAMAN FIBRE LASER, BRAGG FIBRE-OPTICAL GRATING AND METHOD FOR CHANGING THE REFRACTION INDEX IN GERMANIUM SILICATE GLASS

The invention pertains to laser technology, fibre optics and integrated opti cs and has industrial applicability in the field of fibre-optical and waveguide elements made from germano-silicate glass, in particular in fibre-optical Bragg and long- period gratings, dispersion compensators, integrated optical waveguides and so forth. The invention solves the problem of simplifying Raman fibre-optical lasers operating at wavelengths of 1.24 .mu. m and 1.48 .mu.m and enhancing the efficiency of the radiation conversion associated with Raman scattering. The 1.24 .mu.m laser comprises a pumping source (1), a fibre-optical waveguide (2) containing 1-30 Mol % P2O5; sections of the fibre-optical waveguide containing 11-39 Mol % GeO2 form Bragg fibre-optical gratings (3, 4). The grating (3) forms an opaque dispersion mirror of an optical resonator for a first Stokes component, while the grating (4) is an output dispersion mirror for the same resonator; the first Stokes component issues at the output ...

Chalcogenide doping of oxide glasses

FIBEROPTIC HAS MULTIPLE SHEATHS, NETWORK OF BRAGG HAS Fiberoptic, has PERIODELONGUE, REGISTERED IN THIS ONE AND PROCEEDED Of INSCRIPTION OF THIS NETWORK

NETWORK HAS LONG PERIODS IN A FIBEROPTIC AND MANUFACTORING PROCESS

Wavelength sensitive optical sensor network for detecting methane presence

Il s'agit d'un dispositif pouvant comprendre un réflectomètre (3), des capteurs optiques en série (10a , 10b , ...) pour la détection de variations de paramètres physique(s) ou chimique(s) du milieu environnant, lesdits capteurs comportant des réflecteurs optiques spectralement sélectifs (6a ,16a , 6b , 16b , ...) pourvus de moyens opératoires pour modifier les propriétés optiques de la lumière émise, en fonction des paramètres du milieu. Selon l'invention, les capteurs comprennent en outre un coupleur optique (5a , 5b , ...) dont certaines au moins des fibres de sortie sont pourvues desdits réflecteurs optiques pour une réflexion sélective dans le domaine spectral de la lumière incidente. Application notamment pour détecter la présence en excès de gaz dans un milieu ...

Optical fibre long period system production

L'invention se rapporte à un réseau à longues périodes dans une fibre optique. Ce réseau est destiné à permettre la réalisation d'un filtre à couplage de modes. Il est particulièrement caractérisé en ce qu'il présente des variations périodiques du diamètre de la fibre optique et une symétrie de révolution.

FIBER OPTIC SENSOR FOR DETECTING MULTIPLE PARAMETERS IN A HARSH ENVIRONMENT

A fiber optic sensor is provided. The fiber optic sensor includes a fiber core having a plurality of Bragg grating elements wherein, the grating elements comprise a periodic or a quasiperiodic modulated microcrystalline and rigid silicon dioxide tetrahedral structure and a cladding disposed about the fiber core.

ACOUSTO-OPTIC VARIABLE ATTENUATOR WITH ACTIVE CANCELLATION OF BACK REFLECTIONS

An acousto-optic filter includes an optical fiber with a first region and a second region. A first acoustic wave generator is coupled to optical fiber. The first acoustic wave generator produces a first acoustic wave that travels in a first direction in the first region. A backward-propagating wave is generated in response to propagation of the first acoustic wave along the optical fiber. The backward-propagating wave travels in an opposite direction relative to the first acoustic wave. A first acoustic wave propagation member is coupled to the optical fiber. A second acoustic wave generator is coupled to the optical fiber at the second region. The second acoustic wave generator produces a second acoustic wave that combines with the backward propagating acoustic wave.

OPTICAL FILTER

An SC-type optical PAD connector (4) has a ferrule (6) for accommodating a certain length of an optical fiber (5) which comprises a core containing a damping dopant such as Co or V for adjusting the intensity of the received signal within a permissible range and a photosensitive dopant such as Ge or Sn for selectively reflecting the input light and provided with a chirped grating, which is a periodic modulation structure for the refractive index, in the longitudinally middle portion and a cladding formed outside of the core and having a refractive index smaller than that of the core. The certain length of the optical fiber (5) is protected by the ferrule (6) and fitted in a housing (7) and the connector (4) has one end formed into a male connection terminal and the other end formed into a female connection terminal.

ADJUSTABLE BEAM CHARACTERISTICS

Disclosed herein are methods, apparatus, and systems for providing an optical beam delivery system, comprising an optical fiber including a first length of fiber comprising a first RIP formed to enable, at least in part, modification of one or more beam characteristics of an optical beam by a perturbation assembly arranged to modify the one or more beam characteristics, the perturbation assembly coupled to the first length of fiber or integral with the first length of fiber, or a combination thereof and a second length of fiber coupled to the first length of fiber and having a second RIP formed to preserve at least a portion of the one or more beam characteristics of the optical beam modified by the perturbation assembly within one or more first confinement regions. The optical beam delivery system may include an optical system coupled to the second length of fiber including one or more free-space optics configured to receive and transmit an optical beam comprising the modified one or more ...

Method for changing the refraction index in germanium silicate glass

The present invention relates to a method for changing the refractive index in an element comprising germanium silicate glass by irradiating the germanium silicate glass with laser radiation having an associated wavelength in the range of 270 nm to 390 nm for exciting an absorption band in the glass centered at 330 nm. The element may be polymer coated in which instance the glass is irradiated through the polymer coating. In addition, the glass may have been exposed to a hydrogen atmosphere before being irradiated. In either instance, the laser radiation is directed at an angle to the surface of the element or along an optical axis of the element or both. The element may comprise a portion of an optical light guide, such as an optical fiber, or such as an integrated optical waveguide.

Waveguide and connecting element

The invention relates to a waveguide (1) with a first longitudinal section (11), which has at least one core (21) with a first refractive index (nK) and a sheath (22) surrounding said core with a second refractive index (nM), it being possible for at least one optical signal (S) to be guided in the core (21), and the waveguide (1) furthermore has a third longitudinal section (13) with the sheath (22) and a coating (23) surrounding said sheath with a third refractive index (nB), it being possible for the optical signal to be guided in the sheath (22) in the third longitudinal section (13), and the waveguide (1) has a second longitudinal section (12), which connects the first longitudinal section (11) and the third longitudinal section (13) and in which the signal may be conducted over from the core (21) onto the sheath (22).

AN OPTICAL FIBER, A FIBER LASER, A FIBER AMPLIFIER AND ARTICLES COMPRISING SUCH ELEMENTS

Optische Faserstruktur für abhörsichere Übertragung

Optical fiber with tin doped core-cladding interface

Etching optical fibres

A method of tapering a portion of an optical fibre comprises the steps of: suspending the fibre in an etching bath having a layer of cladding etchant suspended between two non-etching liquid layers; and causing relative movement between the fibre and the etching bath so that the layer of cladding etchant moves longitudinally along the fibre with time.

Hydrogen resistant optical fiber/grating structure suitable for use in downholesensor applications

OPTICAL SYSTEMS, DEVICES WITH BRAGG LATTICE AND MANUFACTURING PROCESS

Optical fiber grating device

METHOD FOR MAKING A MULTICOLOR LARGE DIAMETER OPTICAL FIBER WAVEGUIDE

Depressed cladding fiber design for reducing coupling to cladding modes in fiber gratings

Chalcogenide doping of oxide glasses

OPTICAL FILTER

An SC-type optical PAD connector (4) has a ferrule (6) for accommodating a certain length of an optical fiber (5) which comprises a core containing a damping dopant such as Co or V for adjusting the intensity of the received signal within a permissible range and a photosensitive dopant such as Ge or Sn for selectively reflecting the input light and provided with a chirped grating, which is a periodic modulation structure for the refractive index, in the longitudinally middle portion and a cladding formed outside of the core and having a refractive index smaller than that of the core. The certain length of the optical fiber (5) is protected by the ferrule (6) and fitted in a housing (7) and the connector (4) has one end formed into a male connection terminal and the other end formed into a female connection terminal.

OPTICAL FIBER GRATINGS HAVING INTERNAL GAP CLADDING FOR REDUCED SHORT WAVELENGTH CLADDING MODE LOSS

The present invention is predicated on applicants' discovery that an appropriately spaced and dimensioned internal gap cladding can substantially reduce short wavelength cladding mode loss in a fiber Bragg grating. A fiber Bragg grating is provided with a ring of closely spaced, longitudinally extending gap regions in the glass peripherally surrounding the core. The gaps are spaced apart by thin glass webs having a thickness less than a wavelength of the light being transmitted and are disposed peripherally about the core at a distance of 2-10 wavelengths from the core center. The thin webs limit the passage of the light between the gaps. The combination of webs and gaps acts as an internal thin cladding which supports fewer cladding modes than conventional glass cladding and, significantly, provides increased wavelength spacing between the Bragg resonance and the first cladding made resonance.

OPTICAL FIBER GRATING DEVICE

An optical fiber grating device (1) comprising an optical fiber (10) that has a core region (11) having an index of refraction n1 and an outside diameter 2a and having a long-period grating (14), a first clad region (12) surrounding the core region (11) and having an index of refraction n2 and an outside diameter 2b, and a second clad region (13) surrounding the first clad region (12) and having an index of refraction n3 and an outside diameter 2c. The relationship among the indexes of refraction n1, n2, n3 is n1>n2>n3. The relative refractive-index difference .DELTA.n2 of the first clad region (12) with respect to the second clad region (13) is 0.5 % or more. The thickness (c- b) of the second clad region (13) with respect to the cutoff peak wavelength .lambda. ranges from .lambda. to 10.lambda..

OPTICAL FIBER SENSOR BASED ON RETRO-REFLECTIVE FIBER BRAGG GRATINGS

A retro-reflective sensor for sensing mechanical, chemical or temperature related information, is disclosed. The sensor is formed of an optical waveguide suitable for use in-situ in a high temperature environment having a Bragg grating written into a core region thereof with short-pulsed electromagnetic radiation, said optical waveguide having a glass transition temperature substantially higher than that of silica. Preferably the sensor is written into a length of sapphire fiber or within a zirconium waveguide. Preferably the pulse duration of the short pulsed electromagnetic radiation is less than 500 picoseconds.

SIDE-HOLE CANE WAVEGUIDE SENSOR

A side-hole optical cane for measuring pressure and/or temperature is disclosed. The side-hole cane has a light guiding core containing a sensor and a cladding containing symmetrical side-holes extending substantially parallel to the core. The side-holes cause an asymmetric stress across the core of the sensor creating a birefringent sensor. The sensor, preferably a Bragg grating, reflects a first and second wavelength each associated with orthogonal polarization vectors, wherein the degree of separation between the two is proportional to the pressure exerted on the core. The side-hole cane structure self-compensates and is insensitive to temperature variations when used as a pressure sensor, because temperature induces an equal shift in both the first and second wavelengths. Furthermore, the magnitude of these shifts can be monitored to deduce temperature, hence providing the side-hole cane additional temperature sensing capability that is unaffected by pressure. Additionally, the side-hole ...

Photoinduced Grating in B2O3 Containing Glass

OPTICAL FILTER HAVING WAVEGUIDE STRUCTURE

The present invention relates to an optical filter having a waveguide structure constituted by a core region in which a grating for reflecting light of a predetermined wavelength is formed at a predetermined portion and a cladding region which has a lower refractive index than the core region and covers the core region. In particular, this optical filter has a light-absorbing structure for absorbing, of light to be reflected by the grating, a light component radiated from the grating to the cladding region. This lightabsorbing structure is disposed, at least, at a region where the light component radiated from the grating to the cladding region reaches.

Optical Device Formed with Grating Therein, Add/Drop Filter Using Same, and Method of Fabricating Same

A width of a core in an optical waveguide is decreased in accordance with a predetermined value, as a distance of a position of the core to the centre position thereof is decreased. Consequently, a rectangular spectrum property having no ripple is obtained on a lower wavelength side in a reflection grating. In addition, the width of the core is changed at the position Z in the direction of light propagation, while UV light is radiated to the core, so that a periodically-striated distribution of refractive indices having an envelope which is changed in accordance with a value of "¦sin(C~Z)¦/¦C~Z¦" is formed in the core of the optical waveguide, and the phase of light to be propagated in the direction of light propagation is shifted at the position Z as defined below by .pi.. Z=m.pi./C(m=...,-3,-2,-1,1,2,3,...) Thus, a rectangular spectrum property is obtained in a low-reflection grating.

OPTICAL CONNECTOR

RARE-EARTH-DOPED WAVEGUIDE

The present invention is to a method of adapting optical rare-earth-doped waveguide (10) having a plurality of transverse propagation modes, such that in use, signal gains of non-fundamental modes of the waveguide are attenuated relative to a signal gain of a fundamental mode of the waveguide. The waveguide (10) has a light-guiding region (45) defined by a refractive index-modifying dopant, such as Ge, which has a thermal diffusion coefficient at temperature T in the waveguide greater than a thermal diffusion coefficient of the rare-earth dopant at temperature T. The method comprises heating the waveguide (10) at the temperature T such that a concentration profile of the refractive index-modifying dopant becomes broader than a concentration profile of the rare-earth dopant.

Optical fiber and its manufacturing method

An optical fiber which comprises a coating layer disposed outside a bare optical fiber having a core and a cladding and a grating formed in the core of the exposed bare optical fiber by removing the coating layer and its manufacturing method. The optical fiber is provided with a re-coating layer disposed in the exposed bare optical fiber.

Chiral fiber laser apparatus and method

A chiral fiber laser implemented in a fiber Bragg grating mimicking the advantageous optical properties of a cholesteric liquid crystal structure is provided. The dopant, the pitch, the core cross section and dimensions thereof, of the inventive chiral fiber laser as well as the core and cladding materials used in construction thereof, may be advantageously selected and configured to enable the inventive chiral fiber laser to produce lasing at a desirable wavelength. In another embodiment of the inventive chiral fiber laser, a tunable defect is introduced to provide tunable lasing corresponding to the wavelength at the defect mode. Multiple embodiments using coupled fiber optical pumping as well as direct optical pumping for excitation of the inventive chiral fiber laser are provided.

Multi-Core Fiber Grating Sensor

A twin core fiber for sensor applications is developed. It is particularly useful in de-coupling the strain and temperature and thus obtaining both measurement parameters at the same time and location. It is also particularly useful for measuring the temperature in a high humidity environment. The twin core fiber has two cores and each of the cores having a different dopant regime. Also, each of the cores includes a grating having substantially the same grating period.

Tunable microfluidic optical fiber devices and systems

A tunable optical fiber device comprises a length of fiber having a core having a certain refractive index; a cladding peripherally surrounding the core with a refractive index less than the refractive index of the core; and at least one hollow region disposed within the cladding in proximity to the core or within the core itself. Fluid (typically liquid) controllably moved within the hollow region modifies the effective index of the fiber and thereby tunes its characteristics.

An optical waveguide and method for creating an asymmetrical optical filter device

FIBER BRAGG GRATING ELEMENT

The present invention provides a fiber Bragg grating element which is simply configured and capable of obtaining a high cut-off amount exceeding 40 dB in a wide range. A fiber Bragg grating element of the present invention has a plurality of gratings formed in an optical waveguide having a core and a cladding around the core thereby to perform high rejection filtering on an input optical signal over a desired bandwidth, the gratings being formed with a grating pitch between adjacent two of the gratings increasing toward a center in a longitudinal direction of the optical waveguide.

An optical waveguide and method for creating an asymmetrical optical filter device

The invention is related to an optical waveguide device comprising a length of fiber including a monomode core having a refraction index of nco, a photosensitivity of Sco and a radius Rco and an internal cladding with an refractive index of ncl, a photosensitivity of Scl and a radius of Rcl, and a outer cladding surrounding the internal cladding with an refractive index that allows the existence of multiple cladding modes, and a slanted Bragg grating with an effective tilt angle of θ written in core and inner cladding of the optical waveguide, coupling the fundamental mode into several cladding modes where Rcl ≤ 2.5 Rco and the Sco ≤ Scl.

ФОТОЧУВСТВИТЕЛЬНЫЙ ВОЛОКОННЫЙ СВЕТОВОД И ФОТОИНДУЦИРОВАННАЯ СТРУКТУРА

Изобретение используется в волоконных лазерах различных конфигураций, в том числе в лазерах с накачкой в оболочку световода, каскадных лазерах и конвертерах на вынужденном комбинационном рассеянии, спектральных фильтрах, компенсаторах дисперсии, датчиках физических величин (показателя преломления, температуры, механических напряжений), элементах для подавления излучения на заданных длинах волн, эрбиевых волоконных усилителях спонтанной люминесценции в области 1,06 мкм, неодимовых усилителях, для сглаживания спектра усиления эрбиевых волоконных усилителей, используемых, в частности, в системах со спектральным уплотнением каналов. Сердцевина волоконного световода содержит 0,01 - 5 вес.% атомов серы. На световод воздействуют излучением лазера с длиной волны короче 240 нм, причем плотность лазерного излучения не превышает 100 мДж/см2. Повышена фоточувствительность волоконного световода, упрощена технология изготовления фотоиндуцированных структур в нем. 2 c. и 8 з.п. ф-лы, 4 ил.

Древовидный оптический разветвитель без потерь на обратном отражении и с нулевыми коэффициентами передачи и направленности для волоконно-оптических систем связи

Изобретение относится к волоконно-оптическим разветвительным устройствам и может быть использовано в волоконно-оптических сетях информационного обмена. Древовидный оптический разветвитель без потерь на обратном отражении и с нулевыми коэффициентами передачи и направленности для волоконно-оптических систем связи содержит волоконные световоды на основе кварцевого стекла и отражающее сферическое покрытие. Древовидный оптический разветвитель имеет сферическую форму и изготовлен из кварцевого стекла с показателем преломления n = 1,46–1,49. Он состоит из двух частей сферы с нанесенным на их внешнюю сферическую поверхность отражающим покрытием, при этом каждая часть сферы включает отражающие зеркальные экраны, площадями, не позволяющими излучению от входного волоконного световода напрямую взаимодействовать с выходными волоконными световодами. Части сферы соединены с помощью клея, имеющего такой же показатель преломления, что и кварцевое стекло, и полностью покрыты после склеивания таким же отражающим ...

Optische Faserstruktur für abhörsichere Übertragung

OPTISCHE WELLENLEITERVORRICHTUNG

Optical fibre for maximising residual mechanical stress and method of fabricating optical fibre gratings using the same

Evanescent sensor using a hollow-core ring mode waveguide

Chirped tapered optical fibre filter bearing a grating

A chirped distributed Bragg grating optical fibre filter comprises an adiabatically tapered single mode optical fibre 23 provided on the taper 21 with a distributed Bragg grating of uniform pitch. ...

Long-period optical fiber grating written in multi-cladding optical fiber

AN OPTICAL TRANSVERSE ELECTROMAGNETIC WAVE AND MANUFACTURING PROCESS FOR AN ASYMMETRICAL OPTICAL FILTER DEVICE

CHIRALE FIBER LASER DEVICE AND PROCEDURE

Slant-type fiber grating

An embodiment of the present disclosure relates to a slant-type fiber grating (SFG) which can easily implement a gain equalizer with high performance. The SFG includes an optical fiber which is formed of silica glass including: a core; a first clad including a photosensitive material; and a second clad. A specific section, which is positioned between two different points arranged along the fiber axis of the optical fiber, includes: a first area including a slanted Bragg grating installed in an area corresponding to the first clad; a pair of second areas disposed such that the first area is interposed therebetween; and third areas disposed such that the first area and the pair of second areas are interposed therebetween. MFDs at a wavelength of 1.55 ㎛ in the third areas are smaller than an MFD at a wavelength of 1.55 ㎛ in the first area.

Depressed cladding fiber design for reducing coupling to cladding modes in fibergratings

EVANESCENT SENSOR USING A HOLLOW-CORE RING MODE WAVEGUIDE

Method and apparatus enable optical evanescent sensing utilizing a waveguide with an annular core. The annular core can provide detectable sensitivity to a measurand due to optical interactions with contents along an inside surface of the annular core since optical properties of the contents vary with changes in the measurand.

BRAGG GRATING MADE IN OPTICAL WAVEGUIDE

A bragg grating is made in an optical path composed of material exhibiting change in index when exposed to radiation of an actuating frequency by passing radiation from a source of such actuating frequency through a mask with periodic variation in transmission, phase, or other optical properties to expose the material of t he path to a diffraction pattern.

OPTICAL FIBER GRATING

The present invention relates to an optical fiber grating as an optical component comprising an optical fiber having a core and a cladding, and a grating photowritten in the optical fiber. In particular, in the optical fiber grating in accordance with the present invention, the optical fiber into which the grating periodically changing the refractive index in the waveguide along the advancing direction of light is photowritten has a depressed cladding type refractive index profile. Accordingly, when the configuration of the optical fiber having a depressed cladding type refractive index, employed as the object in which the grating is photowritten, is changed, the stability in characteristics as the optical component or the like can easily be improved.

WAVELENGTH SELECTIVE GRATING ASSISTED OPTICAL COUPLERS

A wavelength selective optical fiber coupler having various applications in the field of optical communications is disclosed. The coupler is composed of dissimilar waveguides (12, 22) in close proximity. A light induced, permanent index of refraction grating (42) is recorded in the coupler waist (52). The grating filters and transfers energy within a particular range of wavelengths from a first waveguide (12) to a second waveguide (22). Transversely asymmetric gratings provide an efficient means of energy transfer. The coupler can be used to combine or multiplex a plurality of lasers operating at slightly different wavelengths into a single fiber. Other embodiments such as a dispersion compensator and gain flattening filter are disclosed.

OPTICAL DEVICE COMPRISING OF THE SENSORS AND SELECTIVE REFLECTORS SPECTRALEMENT

FIBEROPTIC DESIGNED TO PRODUCE FILTERS EQUALIZING OF AMPLIFYING GAIND' HAS FIBRE DOPEE

Doped photosensitive optical fibre with reduced transmission loss

L'invention concerne une fibre photosensible comprenant un coeur (1) et une gaine (4) comportant une couche intérieure (2) et une couche extérieure (3), le coeur au moins étant photosensible pour former un réseau. Dans cette fibre photosensible, le coeur (1) et la couche intérieure (2) de la gaine (4) comprennent un agent de dopage photosensible pour augmenter l'indice de réfraction; le coeur (1) comprend un également un premier agent de dopage non photosensible pour augmenter l'indice de réfraction, et la couche intérieure (2) de la gaine (4) comprend un second agent de dopage non photosensible pour diminuer l'indice de réfraction.

FIBEROPTIC HAS MULTIPLE SHEATHS, NETWORK OF BRAGG HAS Fiberoptic, HAS LONG PERIOD, REGISTERED VOTER IN THIS ONE AND PROCEEDED Of INSCRIPTION OF THIS NETWORK

La fibre comprend un coeur (40) en silice dopée au germanium, une gaine intérieure (42) en silice dopée au fluor ayant un indice de réfraction inférieur à celui du coeur et entourant le coeur et une gaine extérieure (44) en silice ayant un indice de réfraction inférieur à celui du coeur et supérieur à celui de la gaine intérieure et entourant la gaine intérieure. Pour inscrire le réseau l'indice de réfraction du coeur est périodiquement modulé en recuisant périodiquement la fibre.

Method of manufacturing optical waveguide

CHIRAL FIBER BRAGG GRATING

A fiber Bragg grating comprises a chiral fiber (10) mimicking a cholesteric liquid crystal structure, having a first and a second helical structures (22,24) disposed along its central longitudin al axis, where the second helical structure (24) is identical in orientation to the first helical structure (22) but is shifted by one half of the structure's pitch forward. In another embodiment of the invention, only a single helical structure is disposed along the fiber to create an optically resonant chiral fiber.

OPTICAL FIBER WITH PRIMARY AND SECONDARY CLADDINGS HAVING DIFFERENT REFRACTIVE INDICES

An optical fiber has a core with a diameter Dc and a refractive index nc; a primary cladding concentrically surrounding the core and having an outer diameter dpc and a refractive index npc less than the core refractive index nc; and a secondary cladding concentrically surrounding the primary cladding and having an outer diameter dsc and a refractive index nsc less than the primary cladding refractive index npc.

OPTICAL WAVEGUIDE DEVICE

Tin-doped photosensitive optical glass is disclosed, together with applications of the glass in fabricating waveguides and waveguide devices such as Bragg gratings.

Microstructured optical waveguide for providing periodic and resonant structures

A microstructured optical waveguide is formed to include a periodic sequence of “plugs” of optically active material within the inner cladding air tunnels. The plugs are utilized as a grating structure for generating resonant and periodic structures. The waveguide (in one embodiment, an optical fiber) is tunable by changing the spacing of the plugs (e.g., heating the structure, changing the pressure within the structure, etc.), or by modifying the initial spacing of the plugs during the formation of the microstructured optical waveguide (i.e., by modifying the “dipping frequency” of the waveguide into a reservoir of optically active material). In general, any number of different types of optically active material may be used to form the plugs, where two or more different materials may be used in the same structure, and introduced in an alternating fashion.

METHOD FOR DETERMINING THE CURVATURE AND/OR TORSION OF AN OPTICAL WAVEGUIDE

A method for determining a curvature and/or torsion of an optical waveguide of a fibre-optic sensor, comprising at least two Bragg gratings introduced into the optical waveguide and extending through a common cross-sectional plane, situated in a radial direction, through the optical waveguide, wherein the Bragg gratings are introduced in the core and/or on the boundary between the core and the cladding and/or in an inner edge region of the cladding within an evanescence region of the light, the method comprising: providing reference data of intensities of reflected light portions of light coupled into the optical waveguide, in particular depending on known reference deformations of the optical waveguide, measuring at least one light intensity of reflected light portions of light coupled into the optical waveguide, wherein the optical waveguide has a deformation to be determined, and determining the deformation by comparing the light intensity with the reference data.

Holographic mirror for optical interconnect signal routing

A holographic mirror 10 for re-directing an optical signal that includes a base 14 having an outer surface 16, and a plurality of discrete nano-structures 12 formed into the outer surface of the base. Each nano-structure has an out-of-plane dimension 20 that is within an order of magnitude of one or both in-plane dimensions 22. The plurality of nano-structures are configured in a repeating pattern with a predetermined spacing 18 between nano-structures for re-directing an optical signal.

Grating inscribing in optical waveguides

There is described herein a method and system for inscribing gratings in optical waveguides. The waveguides may be hydrogen-free, germanium-free, low germanium, low hydrogen, and a combination thereof. Such gratings written in hydrogen-free fibers are suitable for sensor applications in which the use of hydrogen for photosensitizing fibers is undesirable owing to their increased sensitivity to nuclear radiation. The grating are formed by at least one pulse having a wavelength comprised between about 203 nm and about 240 nm. The laser source may be a Continuous Wave (CW) laser source or a pulsed laser source generating at least one pulse having a width in the order of nanoseconds (10 9 ).

Method and apparatus for fiber delivery of high power laser beams

In various embodiments, an optical fiber includes a core having a relatively large area selected so as to raise a threshold of stimulated Raman scattering or stimulated Brillouin scattering, or both, the core having a high aspect ratio elongated cross-section and having a first refractive index. The core is narrower in a fast-axis direction and wider in a slow-axis direction, such that the fiber is mechanically flexible in the fast-axis direction and is mechanically rigid in the slow-axis direction.

Optical connector with ferrule interference fit

An optical connector for operation within a temperature range, comprising: (a) a ferrule comprising a first material having a coefficient of thermal expansion COE-1, and a diameter no greater than a diameter d1 below a transition temperature Ts within the temperature range and no less than a diameter d2 above Ts; (b) a spring disposed behind and in contact with the ferrule to apply a forward force to the ferrule; and (c) a housing comprising a second material having a coefficient of thermal expansion COE-2 and defining a bore hole having a diameter greater than d2, and an interface having a restricted bore hole having a diameter no greater than a diameter d3 below Ts, and no less than a diameter d4 above Ts, wherein connector configuration is COE-2>COE-1 with d>d3 and d2<d4 or COE-2<COE-1 with d1<d3 and d2>d4.

Fiber laser

The optical fiber of the present invention has an input double-clad fiber containing high-reflection FBG, an oscillation double-clad fiber, and an output double-clad fiber containing low-reflection FBG. The output double-clad fiber is formed of a core, a first clad, and a second clad. In the output double-clad fiber, a high refractive-index resin coat section recoated with high refractive-index resin whose refractive index is the same as that of the second clad or greater is disposed at a part where the second clad is partly removed between an output end and the low-reflection FBG. The refractive index of the high refractive-index resin coat section gradually increases along the direction in which light travels through the first clad.

OPTICAL FIBER AND MANUFACTURING METHOD THEREOF

An optical fiber has an incident end on which light is incident, an emitting end from which the light is emitted, and an aperture provided in a core located at or near the emitting end. The aperture is formed by irradiating the core with an ultrashort pulsed laser beam having pulse widths of 10seconds to 10seconds. 1. An optical fiber comprising:an incident end on which light is incident;an emitting end from which the light is emitted; andan aperture provided in a core located at or near the emitting end,{'sup': −15', '−11, 'wherein the aperture is formed by irradiating the core with an ultrashort pulsed laser beam having pulse widths of 10seconds to 10seconds.'}2. The optical fiber according to claim 1 ,wherein the aperture includes a light scattering region, andwherein the light scattering region is formed by inducing a damage change in part of the core through the irradiation of the ultrashort pulsed laser beam.3. The optical fiber according to claim 1 ,wherein the aperture includes a light absorption region, andwherein the light absorption region is formed by inducing blackening in part of the core through the irradiation of the ultrashort pulsed laser beam.4. The optical fiber according to claim 1 ,wherein the aperture has a disc shape, andwherein the aperture includes an opening in a center thereof so as to surround an axis line of the core.5. The optical fiber according to claim 4 , wherein the plurality of apertures are provided along the axis line of the core while separated from each other.6. The optical fiber according to claim 1 ,wherein the aperture has a cylindrical shape, andwherein the aperture includes a hollow portion so as to surround the axis line of the core.7. The optical fiber according to claim 6 , wherein the plurality of apertures are provided along a direction orthogonal to the axis line of the core while separated from each other.8. The optical fiber according to claim 1 , wherein an optical element is provided on the emitting end side of ...

Microlayer Coextrusion of Optical End Products

The disclosed embodiments generally relate to extruding multiple layers of micro- to nano-polymer layers in a tubular shape. In particular, the aspects of the disclosed embodiments are directed to a method for producing a Bragg reflector comprising co-extrusion of micro- to nano-polymer layers in a tubular shape. 1. A method for producing a Bragg reflector comprising co-extrusion of micro- to nano-polymer layers in a tubular shape.2. A method according to claim 1 , wherein said tubular shape contains a core.3. A method according to claim 2 , wherein said core is hollow.4. A method according to claim 2 , wherein said core comprises a transmissible polymer.5. A method according to wherein said layers are of constant thickness.6. A method according to claim 1 , wherein said layers are of varying thickness.7. A method according to claim 1 , wherein said layers are of Chirped gradient thickness.8. A method according to claim 5 , wherein said layer thickness is ¼ the wavelength of the desired output wavelength.9. A method according to claim 1 , wherein said layers comprise polymers with different refractive indices.10. A method according to claim 1 , wherein said tube comprises an outer cladding.11. A method according to claim 1 , wherein at least one layer is surrounded by two Bragg reflector layers.12. A method according to claim 11 , wherein said Bragg reflecting layers are of constant thickness.13. A method according to claim 12 , wherein said Bragg reflecting layers are Chirped.14. A method according to claim 11 , comprising an outer cladding.15. A method according to claim 11 , comprising an inner cladding.16. A Bragg reflector comprising co-extruded micro- to nano-polymer layers in a tubular shape.17. A Bragg reflector according to claim 16 , wherein said tubular shape contains a core.18. A Bragg reflector according to claim 17 , wherein said core is hollow.19. A Bragg reflector according to claim 18 , wherein said core comprises a transmissible polymer.20. A Bragg ...

Apparatus for measuring state variables

An apparatus for measuring state variables with at least one fiber-optic sensor, containing at least one optical coupler, at least one filter element and at least one photoelectric converter, where the optical coupler, the filter element and the photoelectric converter are integrated on a substrate, and the filter element contains at least one Bragg grating which is designed to supply the light portion reflected by the Bragg grating to the photoelectric converter.

Temperature Sensor

A temperature sensor and temperature sensing system for sensing changes m temperature up to a predetermined temperature is disclosed. The temperature sensor includes a microstructured optical fiber where the micro-structured optical fiber includes a plurality of longitudinal channels extending along the microstructured optical fiber. The sensor also includes a fiber Bragg grating formed in the microstructured optical, fiber by generating a periodic modulation in the refractive index along a core region of the microstructured optical fiber. The fiber Bragg grating is operable to produce band reflection at a reflection wavelength that varies in accordance with changes in temperature at the core region of the optical fiber. 1. A temperature sensor for sensing changes in temperature up to a predetermined temperature , comprising:a microstructured optical fiber, the microstructured optical fiber including a plurality of longitudinal channels extending along the microstructured optical fiber; anda fiber Bragg grating formed in the microstructured optical fiber by generating a periodic modulation in the refractive index along a core region of the microstructured optical fiber, wherein the fiber Bragg grating is operable to produce band reflection at a reflection wavelength that varies in accordance with changes in temperature at the core region of the optical fiber.2. The temperature sensor of claim 1 , wherein the periodic modulation in the refractive index along the core region is formed by laser ablating defects along the core region of the microstructured optical fiber.3. The temperature sensor of claim 2 , wherein the structure of the microstructured optical fiber is configured to facilitate the laser ablating defects along the core region of the microstructured optical fiber.4. The temperature sensor of claim 3 , wherein the structure of the microstructured optical fiber includes a single longitudinal channel extending between the core region and an outer cladding ...

METHOD FOR MAKING AN OPTICAL ELEMENT HAVING A TEXTURED SURFACE AND AN OPTICAL ELEMENT HAVING A TEXTURED SURFACE

There is provided a method for making an optical element having a textured surface. The method comprises the steps of: a) providing a plurality of primary optical fiber segments, each primary fiber segment comprising one or more cores; b) bundling the primary fiber segments into an assembly with the cores of said primary fiber segments extending parallely; c) transforming the assembly into a secondary structure comprising the parallely extending cores; and d) etching a surface of the secondary structure according to an etch profile of said secondary structure, the etch profile being defined by the parallely extending cores, thereby forming the textured surface of the optical element. An optical element having a textured surface is also provided. 1. A method for making an optical element having a textured surface , comprising the steps of:a) providing a plurality of primary optical fiber segments, each primary fiber segment comprising one or more cores;b) bundling the primary fiber segments into an assembly with the cores of said primary fiber segments extending parallely;c) transforming the assembly into a secondary structure comprising the parallely extending cores; andd) etching a surface of the secondary structure according to an etch profile of said secondary structure, the etch profile being defined by the parallely extending cores, thereby forming the textured surface of the optical element.2. The method according to claim 1 , wherein step a) comprises the substeps of:providing a primary optical fiber; andsectioning the primary optical fiber into the plurality of primary optical fiber segments.3. The method according to claim 2 , wherein step a) further comprises a substep of removing a cladding surrounding a primary perform comprising the one or more cores claim 2 , the primary preform being drawn into the primary optical fiber.4. The method according to claim 1 , wherein the one or more cores of the primary optical fiber segments provided in step a) have an ...

METHOD FOR MANUFACTURING AN OPTICAL DEVICE

An embodiment optical device includes a glass plate, a first trench disposed in the glass plate, and a second trench disposed in the glass plate. The second trench crosses the first trench, and the first trench has an open end in a first wall of the second trench. The optical device includes a waveguide disposed inside the first trench, where the waveguide is formed of a material having a refractive index different from that of the glass plate, and a mirror on a second wall of the second trench opposite the first wall and waveguide. The optical device includes an encapsulation layer filling the second trench and covering all of an upper surface of the waveguide and having a refractive index that is different from the waveguide and the glass plate.

CHIRAL FIBER GRATING-BASED POLARIZATION-INDEPENDENT ORBITAL ANGULAR MOMENTUM MODULATOR, PREPARATION METHOD THEREFOR, AND ORBITAL ANGULAR MOMENTUM BEAM GENERATOR

A polarization-independent orbital angular momentum modulator based on a chiral fiber grating, a method for manufacturing the same, and an orbital angular momentum beam generator. The orbital angular momentum modulator includes an optical fiber body having a spiral fiber structure, and the spiral fiber structure has a long-period optical fiber grating effect. The optical fiber body has a periodic spiral refractive index modulation in an axial direction. A period of the spiral refractive index modulation has a magnitude of hundreds of microns, and the spiral refractive index modulation is distributed in an axial direction, a radial direction, and an angular direction of the optical fiber body, and configured to excite a spiral phase to generate an orbital angular momentum beam 1. A polarization-independent orbital angular momentum modulator , comprising:an optical fiber body having a spiral optical fiber structure having a long-period optical fiber grating effect;wherein the optical fiber body has a periodic spiral refractive index modulation in an axial direction; a period of the spiral refractive index modulation has a magnitude of hundreds of microns; and the spiral refractive index modulation is distributed in an axial direction, a radial direction, and an angular direction of the optical fiber body, and configured to excite a spiral phase to generate an orbital angular momentum beam.2. The polarization-independent orbital angular momentum modulator according to claim 1 , wherein the optical fiber body is a dual-mode optical fiber or a quad-mode optical fiber.3. The polarization-independent orbital angular momentum modulator according to claim 1 , wherein the optical fiber body has an axial and periodic spiral refractive index modulation with uniform depth claim 1 , and an amount of the spiral refractive index modulation ranges from 1×10to 1×10.4. The polarization-independent orbital angular momentum modulator according to claim 1 , wherein the optical fiber body ...

UV-Transparent Optical Fiber Coating For High Temperature Application, And Fibers Made Therefrom

An optical fiber having at least two polymer coatings, the optical fiber comprising: an optical fiber comprising a glass optical core and a glass cladding; a first polymer coating comprising a silicone polymer covering the optical fiber; and a second polymer coating covering the first polymer coating is provided. 1. An optical fiber having at least two polymer coatings , the optical fiber comprising:an optical fiber comprising a glass optical core and a glass cladding;a first polymer coating comprising a silicone polymer covering the optical core; anda second polymer coating covering the first polymer coating.2. The optical fiber of claim 1 , wherein the first polymer coating is disposed on and in intimate contact with the glass cladding.3. The optical fiber of claim 1 , wherein the second polymer coating comprises a polymer selected from acrylates claim 1 , aliphatic polyacrylates claim 1 , silsesquioxanes claim 1 , alkyl substituted silicones claim 1 , vinyl ethers claim 1 , or a combination comprising at least one of the foregoing.4. The optical fiber of claim 3 , wherein the second polymer coating comprises a vinyl ether polymer claim 3 , acrylate polymer claim 3 , epoxy polymer claim 3 , or urethane acrylate polymer.5. The optical fiber of claim 1 , wherein the second polymer coating is a vinyl ether polymer and the vinyl ether polymer has a number average molecular weight of at least 10 claim 1 ,000 grams per mole.6. The optical fiber of claim 1 , wherein the first polymer coating has a thickness on the optical fiber of between 20 and 80 micrometers.7. The optical fiber of claim 1 , wherein the second polymer coating has a thickness on the optical fiber of between 2 and 35 micrometers.8. The optical fiber of claim 1 , wherein the first and second polymer coatings have a combined thickness on the optical fiber of between 22 and 115 micrometers.9. The optical fiber of claim 1 , wherein the first polymer coating remains flexible at a temperature from -115 to 204° ...

GENERATION OF ARBITRARY OPTICAL FILTERING FUNCTION USING COMPLEX BRAGG GRATINGS

A waveguide Bragg grating includes a silicon substrate defining a length, a width and a depth and a silicon dioxide (SiO) cladding over the silicon substrate and encasing a silicon nitride (SiNi) core extending along the length of the silicon substrate and defining a variable width and thickness; wherein the silicon nitride (SiNi) core is configured as and functions as a complex Bragg grating waveguide. The waveguide Bragg grating is designed by determining a grating profile of the silicon nitride (SiNi) core from a Layer Peeling algorithm and a Layer Adding algorithm; and mapping the grating profile to a 1-layer waveguide structure with varying width dimensions. The method further relates the grating profile to an effective index variation and maps the range of the effective index variation to the structure. The width corresponds to a single specific effective index. A method of manufacturing is also disclosed. 1. A waveguide Bragg grating comprising:a silicon substrate defining a length, a width and a depth; and{'sub': '2', 'a silicon dioxide (SiO) cladding over the silicon substrate and encasing'}{'sub': 3', '4, 'a silicon nitride (SiNi) core extending along the length of the silicon substrate and defining a variable width and thickness;'}{'sub': 3', '4, 'wherein the silicon nitride (SiNi) core is configured as and functions as a complex Bragg grating waveguide.'}2. The waveguide Bragg grating according to claim 1 , wherein the thickness of the silicon nitride (SiNi) core ranges from 40-400 nm.3. The waveguide Bragg grating according to claim 2 , wherein the thickness of the silicon nitride (SiNi) core is 100 microns (μm).4. The waveguide Bragg grating according to claim 1 , wherein the waveguide Bragg grating is designed by:{'sub': 3', '4, 'determining a grating profile of the silicon nitride (SiNi) core from a Layer Peeling algorithm and a Layer Adding algorithm; and'}mapping the grating profile to a 1-layer waveguide structure with varying width dimensions.5. ...

APPARATUS FOR OPTICAL APPLICATIONS, SPECTROMETER SYSTEM AND METHOD FOR PRODUCING AN APPARATUS FOR OPTICAL APPLICATIONS

The present invention relates to an apparatus for optical applications, a spectrometer system and method for producing an apparatus for optical applications, and in particular to an apparatus comprising an optical waveguide having a first refractive index along a light propagation axis interrupted by a plurality of scattering portions having a second refractive index. Each scattering portion has a long axis substantially perpendicular to the light propagation axis as well as a short axis substantially perpendicular to the light propagation axis and the long axis. A receiver unit or a transmitter unit is arranged on a side of the optical waveguide, the long axis being substantially perpendicular, i.e. normal to the plane of this side on which the receiver unit or transmitter unit is arranged. Accordingly, simplification and miniaturization of an optical apparatus can be realized. 1. An apparatus for optical applications , comprisingan optical waveguide configured to guide light along a light propagation axis and having a first refractive index along the light propagation axis interrupted by a plurality of portions having a second refractive index, wherein each portion has a long axis substantially perpendicular to the light propagation axis as well as a short axis substantially perpendicular to the light propagation axis and the long axis; anda receiver unit arranged on a side of the optical waveguide,wherein the receiver unit is arranged so as to receive light scattered from the plurality of portions in a scattering direction lying in a main scattering plane defined by the long axis and the light propagation axis.2. An apparatus for optical applications , comprisingan optical waveguide configured to guide light along a light propagation axis and having a first refractive index along the light propagation axis interrupted by a plurality of portions having a second refractive index, wherein each portion has a long axis substantially perpendicular to the light ...

Methods and apparatus for determining shape parameter(s) using a sensing fiber having a single core with multiple light propagating modes

Example embodiments include an optical interrogation system with a sensing fiber having a single core, the single core having multiple light propagating modes. Interferometric apparatus probes the single core multimode sensing fiber over a range of predetermined wavelengths and detects measurement interferometric data associated with the multiple light propagating modes of the single core for each predetermined wavelength in the range. Data processing circuitry processes the measurement interferometric data associated with the multiple light propagating modes of the single core to determine one or more shape-sensing parameters of the sensing fiber from which the shape of the fiber in three dimensions can be determined.

Writing of high mechanical strength fiber bragg gratings using ultrafast pulses and a phase mask

Methods and systems for writing a Bragg grating along a grating region of an optical fiber through a polymer coating of the optical fiber are provided. A light beam of ultrafast optical pulses is impinged on the grating region, the ultrafast optical pulses being characterised by writing wavelength at the grating region to which the polymer coating is substantially transparent The light beam is diffracted through a phase mask so as to form an interference pattern defining the Bragg grating at the grating region of the optical fiber. The light beam is also focussed such that the intensity of the optical pulses is below a damage threshold within the polymer coating, and above an FBG inscription threshold within the grating region of the fiber. Optical fiber having Bragg gratings and improved mechanical are also provided.

Optically uniform fiber, methods of making, and methods of inspecting

Disclosed herein is an optical fiber having an optically uniform coating having no physical defects in the coating greater than 100 micrometers in size over a length of 50 meters or greater.

MULTICORE OPTICAL FIBER, FIBER BRAGG GRATING, AND METHOD FOR MANUFACTURING FIBER BRAGG GRATING

The present embodiment relates to an MCF and the like suitable for fabricating an FBG with improved ripple characteristics. The MCF is mainly composed of silica glass, and comprises a plurality of light guiding structures and a common cladding. Each of the light guiding structures includes a core, a first cladding, and a second cladding. The refractive index of the second cladding is higher than that of the first cladding and is lower than those of the core and the common cladding. Further, at least a part of an inner cladding region, constituted by the first cladding and the second cladding, contains a photosensitive material having photosensitivity of changing a refractive index of a glass region containing the photosensitive material in response to irradiation of light with a specific wavelength. 1. A multicore optical fiber which is mainly comprised of silica glass and comprises: a plurality of light guiding structures each extending in a central axis direction; and a single common cladding surrounding the plurality of light guiding structures , whereineach of the plurality of light guiding structures includes:a core extending in the central axis direction;a first cladding provided on an outer periphery of the core, the first cladding having a refractive index lower than a refractive index of the core; anda second cladding provided on an outer periphery of the first cladding, the second cladding having a refractive index higher than the refractive index of the first cladding, lower than the refractive index of the core, and lower than an refractive index of the common cladding, andat least a part of an inner cladding region, constituted by the first cladding and the second cladding, contains a photosensitive material having photosensitivity of changing a refractive index of a glass region doped with the photosensitive material in response to irradiation of light having a specific wavelength.2. The multicore optical fiber according to claim 1 , whereinthe common ...

OPTICAL DISPERSION COMPENSATOR ON SILICON

An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 2×2 splitters to form an optical loop. A second entry port of a first 2×2 splitter is for coupling with an input fiber and a second exit port of a second 2×2 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature. 1. An optical dispersion compensator integrated with a silicon photonics system comprising:a first phase-shifter on a silicon substrate;a second phase-shifter on the silicon substrate;a first 2×2 splitter having a first exit port coupled to an input port of the first phase-shifter and a second exit port coupled to an input port of the second phase-shifter;a second 2×2 splitter having a first entry port coupled to an output port of the first phase-shifter and a second entry port coupled to an output port of the second phase-shifter;a third phase-shifter on the silicon substrate having an input port coupled to a first exit port of the second 2×2 splitter and an output port coupled to a first entry port of the first 2×2 splitter to form an optical loop with the first phase-shifter and the second phase-shifter;wherein the second entry port of the first 2×2 splitter is for coupling with an input fiber and the second exit port of the second 2×2 splitter is for coupling with an output fiber, wherein the optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second ...

Fibre-Optic Sensor and Use Thereof

The invention relates to a fibre-optic sensor comprising an optical waveguide having at least one first core and a cladding surrounding the first core, wherein the first core extends substantially over the entire length of the optical waveguide, wherein the sensor has at least one second core which is at least partly surrounded by the cladding, wherein the longitudinal extent of the second core is less than the total length of the optical waveguide and at least one Bragg grating is introduced into the second core. Furthermore, the invention relates to a use of the fibre-optic sensor. 113-. (canceled)14. A fiber-optic sensor , comprising an optical waveguide , which has at least one first core and a cladding surrounding the first core , wherein the first core extends substantially over the entire length of the optical waveguide , whereinsaid sensor has at least one second core which is at least partly surrounded by the cladding, wherein the longitudinal extension of the second core is less than the total length of the optical waveguide and at least one Bragg grating is arranged in the second core.15. The sensor according to claim 14 , wherein the longitudinal extension of the second core shows:at least one first longitudinal portion which is adapted to allow an optical coupling between the second core and the first core;at least one third longitudinal portion which is guided at a greater distance from the first core than the first longitudinal portion; andat least one second longitudinal portion, which connects the first longitudinal portion and the third longitudinal portion.16. The sensor according to claim 15 , comprising a plurality of second cores claim 15 , each having a third longitudinal portion and are arranged at least at two different distances from the first core.17. The sensor according to claim 14 , wherein upon excitation with laser radiation of a first spectrum the first core is adapted to produce light of a second spectrum claim 14 , wherein the ...

METHOD AND APPARATUS FOR PRODUCING CRYSTALLINE CLADDING AND CRYSTALLINE CORE OPTICAL FIBERS

We provide methods and apparatus for preparing crystalline-clad and crystalline core optical fibers with minimal or no breakage by minimizing the influence of thermal stress during a liquid phase epitaxy (LPE) process as well as the fiber with precisely controlled number of modes propagated in the crystalline cladding and crystalline core fiber via precisely controlling the diameter of crystalline fiber core with under-saturated LPE flux. The resulting crystalline cladding and crystalline core optical fibers are also reported. 1. A method for preparing a crystalline clad and crystalline core optical fiber , comprising:securing a crystalline fiber core having a refractive index and a first end and a second end in a holder with no or minimized thermally induced stress, wherein the first end of the crystalline fiber core is secured in the holder and wherein the second end is free to move in at least an axial direction of the fiber within the holder;immersing the crystalline fiber core into at least one molten liquid phase epitaxy (LPE) solution comprising at least one flux and at least one cladding until a crystalline cladding layer has formed thereon, said crystalline cladding layer having a lower refractive index than the crystalline fiber core refractive index.2. The method of claim 1 , further comprising the molten LPE solution through a 1-dimensional or 2-dimensional mesh type bottom support claim 1 , wherein the molten flux passes through the mesh type bottom support and there is a relative movement between the fiber core preform and mesh bottom support along at least the axial direction of the fiber during an LPE growing process claim 1 , resulting in a uniform cladding growth.3. The method of claim 1 , wherein both the mesh bottom support and the fiber can move within the flux in addition to the relative movement between two.4. The method of claim 1 , wherein the fiber and mesh bottom support is separated while the flux is still at the molten liquid state by ...

MANUFACTURING DEVICE AND MANUFACTURING METHOD OF OPTICAL FIBER GRATING

A manufacturing device of an optical fiber grating to write a grating in a core of an optical fiber by irradiating the optical fiber with laser light includes: a fixing device that fixes the optical fiber to at least one of a first position located more on an upstream side and a second position located more on a downstream side in a conveyance direction of the optical fiber than a laser light irradiating position of the optical fiber in a case of writing the grating; and a feeder having a structure capable of linearly reciprocating in the conveyance direction and adapted to feed a predetermined length of the optical fiber in the conveyance direction in a case where a fixed state of the optical fiber by the fixing device is released. 1. A manufacturing device of an optical fiber grating writing a grating in a core of an optical fiber by irradiating the optical fiber with laser light , the device comprising:a fixing device configured to fix the optical fiber to at least one of a first position located more on an upstream side and a second position located more on a downstream side in a conveyance direction of the optical fiber than a laser light irradiating position of the optical fiber in a case of writing the grating; anda feeder configured to be capable of linearly reciprocating in the conveyance direction and configured to feed a predetermined length of the optical fiber in the conveyance direction in a case where a fixed state of the optical fiber by the fixing device is released.2. The manufacturing device of an optical fiber grating according to claim 1 , whereinthe feeder comprises:a fixed portion having a guide extending in the conveyance direction;a movable portion capable of reciprocating along the guide; anda holder attached to the movable portion and configured to hold the optical fiber.3. The manufacturing device of an optical fiber grating according to claim 2 , wherein the feeder comprises an irradiator attached to the movable portion and configured to ...

MULTI-MATERIAL STRETCHABLE OPTICAL, ELECTRONIC AND OPTOELECTRONIC FIBERS AND RIBBONS COMPOSITES VIA THERMAL DRAWING

The present invention concerns a thermal drawing method for forming fibers, wherein said fibers are made at least from a stretchable polymer. The present invention also concerns drawn fibers made by the process. 126-. (canceled)27. A thermal drawing method for forming a fiber comprising the steps of:providing a preform of a material for the fiber;heating the material such that the preform necks down under its own weight and produces a lower end; andcontinuously drawing a fiber from the lower end of the preform,wherein the material includes a stretchable polymer that is an elastomer.28. The method as defined in claim 27 , wherein the step of continuously drawing includes co-drawing the fiber with another material.29. The method as defined in claim 27 , further comprising the step of:providing an additional element to the fiber, the additional element including at least one of a metallic electrode made of a conductive medium, a semiconducting material, an insulating material, and optical material, and a functional material.30. The method as defined in claim 27 , further comprising the steps of:inserting a thin metallic wire in a channel of the fiber to form an embedded electrode; andencapsulating a connection with the embedded electrode by an adhesive to improve mechanical resistance of the connection.31. The method as defined in claim 27 , wherein the material of the preform further includes nanoscale objects to bring functionality to the material.32. The method as defined in claim 31 , wherein the nanoscale objects include at least one of nanoparticles and nanotubes.33. A fiber claim 31 , which is drawn from a heated preform of a material claim 31 , the material used for the fiber comprising:a stretchable polymer that is an elastomer.34. The fiber as defined in claim 33 , wherein the material forms a cladding that includes nanoscale objects to bring functionality to the material.35. The fiber as defined in claim 34 , wherein the nanoscale objects include at least ...

Fiber Optic Pressure Sensor

A temperature correcting pressure gauge which has a diaphragm having at least one surface coupled to a source of pressure to be measured, the diaphragm first surface having a first FBG from a first optical fiber attached in an appropriately sensitive region of the diaphragm, a FBG from a second optical fiber attached to the opposite surface from the first FBG, the first and second FBGs reflecting or transmitting optical energy of decreasing or increasing wavelength, respectively, in response to an applied pressure. The first and second FBGs have nominal operating wavelength ranges that are adjacent to each other but are exclusive ranges and the FBGs also have closely matched pressure coefficients and temperature coefficients. 114-. (canceled)15. A pressure sensor system comprising:a diaphragm formed by material between a first blind aperture opening on one end of a rod and a second blind aperture opening on an opposite end of the rod, the first blind aperture forming an enclosed chamber configured to be coupled to a source of pressure;an optical fiber having a first fiber Bragg grating (FBG) attached to a sensing region of the diaphragm, the sensing region generating a strain upon application of a pressure to the enclosed chamber;a second FBG attached to a region of the diaphragm which does not generate a stain upon application of a pressure to the enclosed chamber, the second FBG thermally coupled to the first FBG;a controller configured to determine a pressure and optionally a temperature from a reflected or transmitted wavelengths from the first FBG and the second FBG.16. The pressure sensor of where the first FBG and the second FBG are reflection or transmission gratings.17. The pressure sensor of where the diaphragm has a first pressure coupled to the first aperture and a second pressure coupled to the second aperture.18. The pressure sensor of where the first FBG and the second FBG are either coupled to different optical fibers or are coupled to the same ...

Resin composition, optical fiber and method for manufacturing optical fiber

A resin composition includes a base resin containing a urethane (meth)acrylate oligomer, a monomer, and a photopolymerization initiator, and surface-modified inorganic oxide particles having an ultraviolet curable functional group, wherein the content of the surface-modified inorganic oxide particles is 1% by mass or more and 60% by mass or less based on the total amount of the resin composition and the amount of surface modification on the surface-modified inorganic oxide particles is 0.15 mg/m2 or more.

OPTICAL FIBER AND METHOD OF MANUFACTURING THE SAME

An optical fiber includes a core, a depressed inner cladding surrounding the core, and an outer cladding surrounding the inner cladding, where a refractive index profile of the core includes an α power distribution in which an index α is 3.5 or more and 6 or less, a relative refractive index difference Δ of the inner cladding with respect to the adding is set such that an absolute value |Δ| thereof is 0.01% or more and 0.045% or less, a radius r1 of the core and an outer circumference radius r2 of the inner cladding are set such that a ratio r1/r2 thereof is 0.2 or more and 0.6 or less, a cable cutoff wavelength λof 22 m is 1260 nm or less, and a mode field diameter MFD at a wavelength of 1310 nm is 8.6 μm or more and 9.5 μm or less. 1. An optical fiber , comprising:a core;a depressed inner cladding surrounding the core; andan outer cladding surrounding the inner cladding, a refractive index profile of the core comprises an α power distribution in which an index α is 3.5 or more and 6 or less,', {'sup': −', '−, 'a relative refractive index difference Δ of the inner cladding with respect to the outer cladding is set such that an absolute value |Δ| thereof is 0.01% or more and 0.045% or less,'}, 'a radius r1 of the core and an outer circumference radius r2 of the inner cladding are set such that a ratio r1/r2 thereof is 0.2 or more and 0.6 or less,', {'sub': 'cc', 'a cable cutoff wavelength λof 22 m is 1260 nm or less, and'}, 'a mode field diameter MFD at a wavelength of 1310 nm is 8.6 μm or more and 9.5 μm or less., 'wherein2. The optical fiber according to claim 1 , whereinthe refractive index profile of the core comprises an α power distribution in which an index α is 5 or more and 6 or less.3. The optical fiber according to claim 1 , wherein{'sup': −', '−, 'the relative refractive index difference Δ is set such that the absolute value |Δ| thereof is 0.01% or more and 0.03% or less.'}4. The optical fiber according to claim 1 , whereinthe radius r1 and the outer ...

POLYMERIC WAVEGUIDE WITH SINGLE DOPANT

The present invention relates to the use of dopants for polymer optical fibres or polymer waveguides containing the dopants, sensors in the polymer optical fibres or polymer waveguides, which may be used in the biomedical industry for the measurement of different physiological and physical variables. 1. A polymer optical fibre comprising a single dopant material permitting both refractive index increase and photosensitivity enhancement for Fibre Bragg grating (FBG) fabrication , wherein the single dopant material comprises at least two phenyl rings linked by a disulfide bridge.23.-. (canceled)4. A polymer optical fibre as claimed in claim 1 , wherein the one or more of the phenyl rings may be functionalized with one or more groups selected from alkyl claim 1 , substituted alkyl claim 1 , alkenyl claim 1 , substituted alkenyl claim 1 , alkynyl claim 1 , substituted alkynyl claim 1 , phenyl claim 1 , substituted phenyl claim 1 , aryl claim 1 , substituted aryl claim 1 , heteroaryl claim 1 , substituted heteroaryl claim 1 , halo claim 1 , hydroxyl claim 1 , nitro claim 1 , amino claim 1 , alkoxy claim 1 , substituted alkoxy groups claim 1 , or carboxylic acid groups claim 1 , or combinations of any two or more thereof.6. A polymer optical fibre as claimed in claim 5 , wherein the single dopant material is diphenyl disulfide.7. A polymer optical fibre as claimed in claim 1 , comprising alternating integrated light source sections and sensing sections.8. A polymer optical fibre as claimed in claim 7 , wherein the integrated light source sections are doped with a laser dye and the sensing sections are doped with the single dopant material.9. A polymer optical fibre as claimed in claim 1 , wherein between about 0.1 to about 10 mol % of the single dopant material is employed.10. A sensor system comprising a polymer optical fibre according to .11. A sensor system as claimed in claim 10 , wherein the sensor system is a medical sensor system.12. A method of measuring one or ...

EDGE SEALANT CONFINEMENT AND HALO REDUCTION FOR OPTICAL DEVICES

Techniques are described for using confinement structures and/or pattern gratings to reduce or prevent the wicking of sealant polymer (e.g., glue) into the optically active areas of a multi-layered optical assembly. A multi-layered optical structure may include multiple layers of substrate imprinted with waveguide grating patterns. The multiple layers may be secured using an edge adhesive, such as a resin, epoxy, glue, and so forth. A confinement structure such as an edge pattern may be imprinted along the edge of each layer to control and confine the capillary flow of the edge adhesive and prevent the edge adhesive from wicking into the functional waveguide grating patterns of the layers. Moreover, the edge adhesive may be carbon doped or otherwise blackened to reduce the reflection of light off the edge back into the interior of the layer, thus improving the optical function of the assembly. 1. An optical structure comprising:a substrate including an edge grating pattern that is proximal to an edge of the substrate, the edge grating pattern including one or more features arranged to control capillary flow of a material from the edge of the substrate into the edge grating pattern.2. The optical structure of claim 1 , wherein:the edge grating pattern is on a first surface of the substrate; andthe substrate further includes a second grating pattern on a second surface of the substrate.3. The optical structure of claim 2 , wherein the second grating pattern is a functional grating pattern that includes one or more of an orthogonal pupil expander (OPE) region and an exit pupil expander (EPE) region.4. The optical structure of claim 1 , wherein the one or more features are arranged to be substantially perpendicular to the edge of the substrate.5. The optical structure of claim 1 , wherein the one or more features include one or more of a V-shaped grating pattern claim 1 , an S-shaped grating pattern claim 1 , and a rectangular grating pattern.6. The optical structure of ...

Evacuating bragg gratings and methods of manufacturing

Improvements to gratings for use in waveguides and methods of producing them are described herein. Deep surface relief gratings (SRGs) may offer many advantages over conventional SRGs and Bragg gratings, an important one being a higher S-diffraction efficiency. In one embodiment, deep SRGs can be implemented as polymer surface relief gratings or evacuated Bragg gratings (EBGs). EBGs can be formed by first recording a holographic polymer dispersed liquid crystal (HPDLC) grating. Removing the liquid crystal from the cured grating provides a polymer surface relief grating. Polymer surface relief gratings have many applications including for use in waveguide-based displays.

POLYMER MODULATOR AND LASER INTEGRATED ON A COMMON PLATFORM AND METHOD

A monolithic photonic integrated circuit includes a platform, a monolithic laser formed in/on the platform, and an electro-optic polymer modulator monolithically built onto the platform and optically coupled to the monolithic laser. The polymer modulator is optically coupled to the monolithic laser by waveguides including electro-optic polymer waveguides. The electro-optic polymer modulator and the electro-optic polymer waveguides including an electro-optic polymer core and top and bottom electro-optic polymer cladding layers. The electro-optic polymer core having an electro-optic coefficient (r) greater than 250 pm/v, and a Tg 150° C. to >200° C., and the top and bottom electro-optic polymer cladding layers having a Tg approximately the same as the Tg of the electro-optic polymer core. 1. A monolithic photonic integrated circuit comprising:a platform;a monolithic laser formed in/on the platform; anda polymer modulator monolithically built onto the platform and optically coupled to the monolithic laser.2. The monolithic photonic integrated circuit as claimed in wherein the monolithic laser includes one of a distributed feedback laser claim 1 , a Fabry-Perot laser claim 1 , a distributed Bragg reflector laser claim 1 , or a tunable laser.3. The monolithic photonic integrated circuit as claimed in wherein the polymer modulator includes a Mach-Zehnder interferometer type modulator.4. The monolithic photonic integrated circuit as claimed in wherein the platform is formed of InP.5. The monolithic photonic integrated circuit as claimed in wherein the polymer modulator is optically coupled to the monolithic laser by one of free space claim 1 , polymer waveguides claim 1 , or semiconductor material waveguides.6. The monolithic photonic integrated circuit as claimed in wherein the polymer modulator is optically coupled to the monolithic laser by waveguides including InP waveguides.7. The monolithic photonic integrated circuit as claimed in wherein the polymer modulator is ...

AUTOMATED SYSTEM FOR TRANS-JACKET FIBRE BRAGG GRATING INSCRIPTION AND MANUFACTURING

There is provided an alignment system and method for use in an ultrashort pulse duration laser-based Fiber Bragg Grating (FBG) writing system, the alignment system comprising: clamps configured to hold a coated optical fiber in a position perpendicular to a beam path of an ultrashort pulse duration laser-based FBG writing station; an optical detector; and a control system with an input from the optical detector and an output to adjust parameters of an optical source and the FBG writing station adjust a distance between the optical fiber and an optical source of the writing station based on luminescence generated in a core of the optical fiber as indicated in a signal received at the input from the optical detector. 1. An alignment system for use in an ultrashort pulse duration laser-based Fiber Bragg Grating (FBG) writing system , the electromagnetic radiation having a pulse duration of less than or equal to 5 picoseconds , and the wavelength of the electromagnetic radiation having a characteristic wavelength in the wavelength range from 150 nm to 3.0 microns , the alignment system comprising:a holder configured to hold an optical fiber in a position perpendicular to a beam path of an ultrashort pulse duration laser-based FBG writing station;an optical detector; anda control system with an input from the optical detector and an output to adjust parameters of an optical writing source and the FBG writing station based on photoluminescence generated in the optical fiber as indicated in a signal received at the input from the optical detector.2. The alignment system of claim 1 , wherein the optical fiber is coated.3. The alignment system of claim 1 , wherein an external light source is coupled into the core of the optical fiber.4. The alignment system of claim 3 , wherein the optical detector is positioned to visualize/image ultrashort pulse duration laser induced modification in the optical fiber based on collecting a scattered component of external light source that ...

Side-hole cane waveguide sensor

A side-hole optical cane for measuring pressure and/or temperature is disclosed. The side-hole cane has a light guiding core containing a sensor and a cladding containing symmetrical side-holes extending substantially parallel to the core. The side-holes cause an asymmetric stress across the core of the sensor creating a birefringent sensor. The sensor, preferably a Bragg grating, reflects a first and second wavelength each associated with orthogonal polarization vectors, wherein the degree of separation between the two is proportional to the pressure exerted on the core. The side-hole cane structure self-compensates and is insensitive to temperature variations when used as a pressure sensor, because temperature induces an equal shift in both the first and second wavelengths. Furthermore, the magnitude of these shifts can be monitored to deduce temperature, hence providing the side-hole cane additional temperature sensing capability that is unaffected by pressure. Additionally, the side-hole cane can be used to measure a differential pressure between a first pressure ported to the side-holes and a second external pressure.

Optical Fiber Device Having Polymer Micronano Structure Integrated in Optical Fiber and Preparation Method Thereof

The present disclosure provides a preparation method of an optical fiber device having a polymer micronano structure integrated in an optical fiber, the method comprising: welding a hollow optical fiber so that the hollow optical fiber is welded between two solid optical fibers, ablating the welded hollow optical fiber utilizing a femtosecond laser ablation technology so that a channel vertical to an inner wall is ablated on the hollow optical fiber, filling a colorless and transparent liquid photoresist material inside the hollow optical fiber which has been ablated so that the inside of the hollow optical fiber is filled with the photoresist material, and polymerizing on the photoresist material inside the hollow optical fiber utilizing a femtosecond laser two-photon polymerization technology. 1. A preparation method of an optical fiber device having a polymer micronano structure integrated in an optical fiber , wherein the method comprises:welding a hollow optical fiber in such a way that the hollow optical fiber is welded between two solid optical fibers;ablating the welded hollow optical fiber utilizing a femtosecond laser ablation technology in such a way that a channel vertical to an inner wall is ablated on the hollow optical fiber;filling a colorless and transparent liquid photoresist material inside the hollow optical fiber which has been ablated in such a way that the inside of the hollow optical fiber is filled with the photoresist material;and polymerizing the photoresist material inside the hollow optical fiber utilizing a femtosecond laser two-photon polymerization technology, and washing the polymerized hollow optical fiber utilizing developing solution to obtain the optical fiber device having the polymer micronano structure integrated in the optical fiber.2. The method of claim 1 , wherein the hollow optical fiber has an outer diameter as same as outer diameters of the two solid optical fibers claim 1 , the hollow optical fiber has an inner ...

MULTICHANNEL OPTICAL COUPLER

The optical fiber coupler array can be capable of providing a low-loss, high-coupling coefficient interface with high accuracy and easy alignment between a plurality of optical fibers (or other optical devices) with a first channel-to-channel spacing, and an optical device having a plurality of closely-spaced waveguide interfaces with a second channel-to-channel spacing, where each end of the optical fiber coupler array can be configurable to have different channel-to-channel spacing, each matched to a corresponding one of the first and second channel-to-channel spacing. Advantageously, the refractive indices and sizes of both inner and outer core, and/or other characteristics of vanishing core waveguides in the optical coupler array can be configured to reduce the back reflection for light propagating from the plurality of the optical fibers at the coupler first end to the optical device at the coupler second end, and/or vice versa. 1. A multichannel optical coupler array for optical coupling of a plurality of optical fibers to an optical device , comprising: a common single coupler housing structure;', {'b': 1', '2, 'claim-text': [{'b': 1', '1', '2, 'an inner vanishing core, having a first refractive index (N-), and having a first inner core size (ICS-) at said first end, and a second inner core size (ICS-) at said second end; and'}, {'b': 2', '1', '2, 'an outer core, longitudinally surrounding said inner core, having a second refractive index (N-), and having a first outer core size (OCS-) at said first end, and a second outer core size (OCS-) at said second end; and'}], 'a plurality of longitudinal waveguides each positioned at a spacing from one another, each having a capacity for at least one optical mode, each embedded in said common single housing structure proximally to said second end, wherein at least one of said plurality of longitudinal waveguides is a vanishing core waveguide configured to be coupled at said first end to one of said plurality of ...

LOW INSERTION LOSS HIGH TEMPERATURE STABLE FIBER BRAGG GRATING SENSOR AND METHOD FOR PRODUCING SAME

Provided is an optical waveguide with an inscribed Bragg grating, where the Bragg grating is stable at high temperature, has low scattering loss and high reflectivity. Also provided is a method for inscribing a Bragg grating in an optical waveguide, the method comprising irradiating the optical waveguide with electromagnetic radiation from an ultrashort pulse duration laser of sufficient intensity to cause a permanent change in an index of refraction within a core of the optical waveguide, where the irradiating step is terminated prior to erasure of a Bragg resonance, and heating the optical waveguide to a temperature and for a duration sufficient to substantially remove a non-permanent grating formed in the optical waveguide by the irradiating step. 1. An optical waveguide with an inscribed Bragg grating prepared according to a method comprising the steps of:providing the optical waveguide;providing electromagnetic radiation from an ultrashort pulse duration laser, wherein the electromagnetic radiation has a pulse duration of less than or equal to 5 picoseconds, and wherein the wavelength of the electromagnetic radiation has a characteristic wavelength in the wavelength range from 150 nm to 2.0 microns;irradiating the optical waveguide with the electromagnetic radiation to form a Bragg grating, the electromagnetic radiation incident on the optical waveguide being sufficiently intense to cause a permanent Type II change of the index of refraction within a core of the optical waveguide when exposed to laser pulses, wherein the irradiating step is carried out for at least a number of pulses sufficient to form first a non-permanent Bragg grating having a Type I-like change in index of refraction within the core of the optical waveguide, and wherein the irradiating step is terminated prior to erasure of a Bragg resonance associated with the Type I-like change in index of refraction, by the irradiating and prior to the growth of a new Bragg resonance characteristic to ...

APPARATUS AND METHOD FOR MANUFACTURING OPTICAL FIBER HAVING BENT PORTION

An optical fiber manufacturing apparatus includes a rotating mechanism including a holding member that holds one side of an optical fiber and a rotating member that rotates the holding member, the optical fiber including a glass fiber portion and a coating layer covering the glass fiber portion; a guiding member secured at a distance from the rotating mechanism and configured to retain the other side of the optical fiber loosely fitted therein; and a heating mechanism configured to heat a part of the glass fiber portion exposed and extending out of the coating layer, the part being interposed between the holding member and the guiding member. By rotating the rotating member counterclockwise by a given angle, the glass fiber portion is drawn from the guiding member and bent with a predetermined curvature while being heated. 1. An apparatus for manufacturing an optical fiber having a bent portion , the apparatus comprising:a rotating mechanism including a holding member that holds one side of an optical fiber and a rotating member that rotates the holding member, the optical fiber including a glass fiber portion and a coating layer covering the glass fiber portion;a guiding member secured at a distance from the rotating mechanism and configured to retain the other side of the optical fiber loosely fitted therein; anda heating mechanism configured to heat a part of the glass fiber portion exposed and extending out of the coating layer, the part being interposed between the holding member and the guiding member.2. The apparatus according to claim 1 , whereinthe holding member holds the glass fiber portion, with the coating layer therebetween, and the guiding member allows the glass fiber portion exposed and extending out of the coating layer to be loosely fitted therein.3. The apparatus according to claim 1 , whereinthe guiding member includes a V-grooved substrate and a flat substrate that are made of glass.4. The apparatus according to claim 1 , whereinthe guiding ...

FIBER BRAGG GRATING INTERROGATOR ASSEMBLY AND METHOD FOR THE SAME

A fiber Bragg grating interrogator assembly, comprising: an optical fiber including a fiber Bragg grating (FBG; ) having a variable Bragg wavelength (λ) and a dynamic range of interest (Δλ) over which the Bragg wavelength (λ) can shift during use; —a light source operably connected to the optical fiber, and configured to illuminate the fiber Bragg grating to solicit a response therefrom; and an response analyzer, including: a spectrally selective device having an input port and a plurality of output ports (-), wherein the input port is operably connected to the optical fiber and wherein each of the output ports is associated with a respective spectral range (Δλ), said spectrally selective device being configured to provide a spectral energy distribution of a response of the fiber Bragg grating received on the input port onto said output ports. 1. A fiber Bragg grating interrogator assembly , comprising:an optical fiber including a fiber Bragg grating having a variable Bragg wavelength and a dynamic range of interest over which the Bragg wavelength can shift during use;a light source operably connected to the optical fiber, and configured to illuminate the fiber Bragg grating to solicit a response therefrom; and a spectrally selective device having an input port and a plurality of output ports, wherein the input port is operably connected to the optical fiber and wherein each of the output ports is associated with a respective spectral range, said spectrally selective device being configured to provide a spectral energy distribution of a response of the fiber Bragg grating received on the input port onto said output ports;', 'wherein the spectrally selective device is configured to split two orthogonal polarization components of incoming light onto substantially non-overlapping spectral ranges in the spectral energy distribution of said output ports, particularly such that each output port has one spectral range for each of the two polarization components,', 'wherein ...

DISTRIBUTED INTRAVASCULAR FIBER BRAGG PRESSURE SENSOR

The present invention relates to a pressure sensing device () comprising an optical fiber (), the optical fiber () comprises a central axis (L) and at least one optical fiber core (), the at least one optical fiber core () having one or more reflective FBG structures, and a coating () surrounding the optical fiber (), the coating () having mechanical properties which are radially asymmetric along the central axis (L). 1. Pressure sensing device comprising:an optical fiber comprising a central axis (L) and at least one optical fiber core, the at least one optical fiber core having one or more reflective FBG structures, and{'sub': 1', '2', '1', '2, 'a coating surrounding the optical fiber, the coating comprising a first annular subsection extending through a first annular sector with azimuth φand a second annular subsection extending through a second annular sector with azimuth φ, wherein the mechanical properties of the first and second annular subsections are different, and wherein the azimuths φand φcomplementarily vary along a portion of the central axis (L).'}2. Pressure sensing device of claim 1 , wherein the pressure sensing device is adapted to determine multiple local pressures along the central axis claim 1 , the local pressures exerting radial forces on the coating.3. Pressure sensing device of claim 1 , wherein the difference between thermal expansion coefficients of the first annular section and the second annular section is below 10% and the difference between Poisson ratios of the first annular section and the second annular is larger than 75%.4. Pressure sensing device of claim 1 , wherein the first and second annular subsections are disposed staggered along the central axis (L) claim 1 , forming at least two longitudinal sections.5. Pressure sensing device of claim 4 , wherein each of the at least two longitudinal sections encompasses at least one reflective FBG structure.6. Pressure sensing device of claim 1 , wherein the azimuths φand φcontinuously ...

FIBER BRAGG GRATING INTERROGATION AND SENSING SYSTEM AND METHODS

Fiber Bragg grating interrogation and sensing used for strain and temperature measurements. A simple, broadband light source is used to interrogate one or more fiber Bragg grating (FBG). Specifically, a packaged LED is coupled to fiber, the light therefrom is reflected off a uniform FBG. The reflected light is subsequently analyzed using a filter and a plurality of Si photodetectors. In particular, the filter is a chirped FBG or an optically coated filter, in accordance with some embodiments. Measurement analysis is performed by ratio of intensities at the plurality of detectors, at least in part. 1. A method for interrogating a fiber Bragg grating comprising:powering a light source with a current;illuminating a fiber Bragg grating with a light pulse;{'sub': '1', 'reflecting a portion of the light pulse centered a first wavelength λ;'}{'sub': '1', 'separating the portion of the light pulse centered at a first wavelength λinto a first and second intensity;'}{'sub': '2', 'filtering the first intensity with a filter centered at a second wavelength λ;'}measuring the filtered first intensity;measuring the second intensity; andcalculating a change in the fiber Bragg grating using the measurement of the first and second intensity.2. The method of claim 1 , wherein the light source comprises a first light emitting diode have a spectral intensity centered about a third wavelength claim 1 , λ.3. The method of claim 2 , wherein the light source further comprises a second light emitting diode have a spectral intensity centered about a fourth wavelength claim 2 , λ.4. The method of claim 1 , wherein the filtering the first intensity with a filter centered at a second wavelength λis performed with an optically coated filter.5. The method of claim 1 , wherein the filtering the first intensity with a filter centered at a second wavelength λis performed with a chirped fiber Bragg grating.6. The method of further comprising calculating a ratio of the first and second intensity.7. The ...

OPTICAL COMPONENT, FIBER LASER UNIT, AND FIBER LASER SYSTEM

An optical component includes: a first fiber having a first end and a second end; a second fiber having a third end and a fourth end; a third fiber having a fifth end and a sixth end; a first coating layer that covers the cladding of the second fiber and has a higher refractive index than that of the cladding of the second fiber; and a first high refractive index layer that covers part of an outer peripheral surface and an end face of the second fiber. The first high refractive index layer has a higher refractive index than that of the cladding of the second fiber. The outer diameter of the cladding of the first fiber is smaller than that of the cladding of the second fiber. The outer diameter of the cladding of the third fiber is smaller than that of the cladding of the second fiber. 1. An optical component comprising: 'the first fiber comprises a core and a cladding that are optically coupled to an optical resonator at the first end;', 'a first fiber having a first end and a second end, wherein'} the third end is connected to the second end, and', 'the second fiber comprises a core and a cladding that are directly connected to the core and the cladding of the first fiber at the third end;, 'a second fiber having a third end and a fourth end, wherein'} the fifth end is connected to the fourth end, and', 'the third fiber comprises a core and a cladding that are directly connected to the core and the cladding of the second fiber at the fifth end;, 'a third fiber having a fifth end and a sixth end, wherein'}a first coating layer that covers the cladding of the second fiber and has a higher refractive index than a refractive index of the cladding of the second fiber; and 'the first high refractive index layer has a higher refractive index than the refractive index of the cladding of the second fiber,', 'a first high refractive index layer that covers, at the fourth end, part of an outer peripheral surface of the cladding of the second fiber and at least part of an end ...

DRAW TOWER GRATING PRODUCTION METHOD AND SYSTEM

A system for producing an optical fiber with inscribed grating array is described. The system comprises a fiber drawing apparatus for drawing an optical fiber, a writing system for inscribing a grating in the optical fiber during the drawing process of the optical fiber and a controller for controlling the driving of the writing system. According to the present invention the fiber drawing apparatus also comprises a fiber length and/or drawing detecting means for determining the fiber length and/or fiber drawing speed and/or a fiber drawing parameter during the drawing process. The controller thereby is configured for capturing information from the fiber length and/or drawing detecting means and for controlling the writing system based on the captured information captured from the fiber length and/or drawing detecting means. 119.-. (canceled)20. A system for producing an optical fiber with inscribed grating , the system comprising:a fiber drawing apparatus arranged for drawing an optical fiber,a writing system comprising:a coherent radiation source anda radiation modulating means, configured for inscribing a grating in the optical fiber during the drawing process of the optical fiber,a controller configured for controlling the driving of the writing system,wherein the fiber drawing apparatus comprises a fiber length and/or drawing detecting means for determining the fiber length and/or fiber drawing speed and/or a fiber drawing parameter during the drawing process, andthe controller being configured for capturing information from the fiber length and/or drawing detecting means and for controlling the writing system based on the captured information captured from the fiber length and/or drawing detecting means.21. The system according to claim 20 , wherein the fiber length and/or drawing detecting means comprises a rotating means for guiding the drawn fiber in a non-slipping mode.22. The system according to claim 21 , wherein the fiber length and/or drawing detecting ...

A method for forming a pressure sensor

A method for forming a pressure sensor is provided wherein an optical fibre is provided, the optical fibre comprising a core, a cladding surrounding the core, and a birefringence structure for inducing birefringence in the core. The birefringence structure comprises first and second holes enclosed within the cladding and extending parallel to the core. A portion of the optical fibre comprising the core and the birefringence structure is encased within a chamber, wherein the chamber is defined by a housing comprising a pressure transfer element for equalising pressure between the inside and the outside of the housing. An optical sensor is provided along the core of the optical fibre. Providing the optical sensor comprises optically inducing stress in the core so that the optical sensor exhibits intrinsic birefringence. The chamber is filled with a substantially non-compressible fluid. Consequently, the birefringence structure is shaped so as to convert an external pressure provided by the non-compressible fluid within the chamber to an anisotropic stress in the optical sensor.

Medical laser device and related methods

A laser delivery device may include a connector portion at a proximal end of the laser delivery device and an optical fiber connecting the connector portion to a distal end of the laser delivery device. The connector portion may include a capillary at least partially surrounding a proximal portion of the optical fiber, and the capillary may include dimples on at least a portion of a circumferential surface thereof.

OPTICAL FIBER FOR FIBER BRAGG GRATING

An optical fiber having a composition that is most suitable from the viewpoint of filter formation time and filter properties of slanted fiber grating (SFG) is provided. An optical fiber made of silica-based glass comprises a core region, which does not contain GeOand includes the optical axis, and a cladding region formed around the core region. The cladding region has a refractive index smaller than that of the core region and contains GeOof 6.8 wt % or more. SFG made with the optical fiber enables base loss of 2 dB or less, peak wavelength shift of 1.2 nm or less, and change of 0.2 nm or less in width at half maximum. 1. An optical fiber made of silica-based glass , comprising:a core region including an optical axis of the fiber and{'sub': '2', 'a cladding region formed around the core region, the cladding region having a refractive index smaller than a refractive index of the core region and containing GeOhaving a concentration of 6.8 wt % or more at least at a part thereof.'}2. An optical fiber according to claim 1 , whereinthe concentration is 7.4% or less.3. An optical fiber according to claim 1 , whereinthe concentration is 8.7% or less.4. An optical fiber according to claim 2 , whereinsaid part of the cladding region has an outer diameter, the outer diameter being 1.5 to 4.0 times larger than a mode field diameter at a wavelength in the C-band.5. An optical fiber according to claim 3 , whereinsaid part of the cladding region has an outer diameter, the outer diameter being 1.5 to 4.0 times larger than a mode field diameter at a wavelength in the C-band.6. An optical fiber according to claim 1 , wherein{'sub': 2', '2', '2', '2, 'said part of the cladding region includes an inner circumference and an outer circumference around the inner circumference, the concentration of GeOat the inner circumference is larger than the concentration of GeOat the outer circumference, and the difference between the GeOconcentration at the inner circumference and the ...

SINGLE FIBER BRAGG GRATING AS DELAY LINE INTERFEROMETER

A delay line interferometer comprising an optical waveguide having a distributed Bragg reflector, e.g. Bragg grating, fabricated therein. The distributed Bragg reflector has a refractive index modulation with a period variation Λ(z) along its length z that is arranged to output in transmission an output optical signal f(t) in response to a input optical signal f(t), wherein the output optical signal f(t) is the result of temporal interference between one or more time-delayed replicas of the input optical signal f(t). In other words, the distributed Bragg reflector is operable to generate and permit temporal interference between two or more time-delayed replicas of the input optical signal f(t). The invention may thus mimic the behaviour of one or more MZIs. 1. A delay line interferometer comprising an optical waveguide having a Bragg grating fabricated therein , the Bragg grating having a refractive index modulation with a period variation Λ(z) along its length z that is arranged to output in transmission an output optical signal f(t) in response to a input optical signal f(t) , wherein the output optical signal f(t) is the result of temporal interference between one or more time-delayed replicas of the input optical signal f(t).2. A delay line interferometer according to claim 1 , wherein the optical waveguide is arranged to support the propagation of optical radiation between an input portion for receiving the input optical signal f(t) and an output portion for transmitting the output optical signal f(t) claim 1 , wherein the Bragg grating is fabricated in the optical waveguide between the input portion and the output portion.3. A delay line interferometer according to claim 1 , wherein the optical waveguide is an optical fibre and the Bragg grating is a fibre Bragg grating (FBG).4. A delay line interferometer according to claim 3 , wherein the optical fibre comprises:a core having a first refractive index, anda cladding layer surrounding the core, the cladding ...

OPTICAL FIBER WITH GRATINGS AND METHODS OF FORMING THEREOF

Embodiments of the current disclosure include small diameter single-mode optical fibers having gratings and methods of forming thereof. In some embodiments, methods of forming a small diameter single-mode optical fibers having gratings include providing an optical fiber having a core and cladding with a combined outer diameter of 100 μm to 125 μm and a coating having a thickness of less than or equal to 20 μm, wherein the coating comprises one of: (i) a high-modulus coating layer surrounding the cladding region; or (ii) a low-modulus coating layer surrounding the cladding region and a high-modulus coating layer surrounding the low-modulus coating layer; and exposing the core, through the coating, to a pattern of ultraviolet radiation to form an optical grating within the core. 1. A method , comprising:providing an optical fiber comprising a core region, a cladding region surrounding the core region and a coating surrounding the cladding region;wherein the core and cladding have a combined outer diameter of 100 μm to 125 μm,wherein the coating has a thickness of less than or equal to 20 μm, and wherein the coating comprises one of: (i) a high-modulus coating layer surrounding the cladding region, wherein the high-modulus coating layer has a Young's modulus of greater than or equal to 0.5 GPa; or (ii) a low-modulus coating layer surrounding the cladding region and a high-modulus coating layer surrounding the low-modulus coating layer, wherein the low-modulus coating layer has a Young's modulus of less than or equal to 5 MPa and the high-modulus coating layer has a Young's modulus of greater than or equal to 0.5 GPa; andexposing the core, through the coating, to a pattern of ultraviolet radiation to form an optical grating within the core.2. The method of claim 1 , wherein a ratio of a thickness of the low-modulus coating layer to a thickness of the high-modulus coating layer is from 0.8 to 1.2.3. The method of claim 1 , wherein the coated optical fiber has a diameter ...

METHOD FOR MANUFACTURING AN OPTICAL DEVICE

The present invention relates to a method for manufacturing an optical device comprising forming a first trench in a glass plate and a second trench perpendicular to the first trench, wherein the first trench has an end opening into the second trench. The trenches are treated with hydrofluoric acid. The first trench is filled with a material to form a waveguide, and a mirror is formed on the wall of the second trench opposite the waveguide. An encapsulation layer is deposited over the glass plate, waveguide and second trench. 1. A method for manufacturing an optical device , the method comprising:forming a first trench in a glass plate according to a design of a waveguide;forming a second trench in the glass plate, wherein the second trench crosses the first trench, and wherein the first trench has an open end in a first wall of the second trench;treating the glass plate and surfaces of the first and second trenches with hydrofluoric acid;covering a second wall of the second trench opposite the first wall with a mirror;filling the first trench with a material having a refractive index different from that of the glass plate to form a waveguide; anddepositing an encapsulation layer over the glass plate, waveguide, and second trench.2. The method according to claim 1 , wherein the first trench and the second trench are formed by laser engraving.3. The method according to claim 2 , wherein the first trench and the second trench are formed using a pulsed laser with a duration of pulses in the range from 2 to 500 femtoseconds.4. The method according to claim 1 , wherein the mirror is inclined relative to vertical.5. The method according to claim 4 , wherein the mirror is inclined at an angle in the range from 40 to 50 degrees relative to vertical.6. The method according to claim 1 , wherein the waveguide and mirror are separated by a distance of less than 50 μm.7. The method according to claim 1 , wherein the refractive index of the glass of the glass plate is lower than ...

ARRAYS OF INTEGRATED ANALYTICAL DEVICES AND METHODS FOR PRODUCTION

Arrays of integrated analytical devices and their methods for production are provided. The arrays are useful in the analysis of highly multiplexed optical reactions in large numbers at high densities, including biochemical reactions, such as nucleic acid sequencing reactions. The integrated devices allow the highly sensitive discrimination of optical signals using features such as spectra, amplitude, and time resolution, or combinations thereof. The arrays and methods of the invention make use of silicon chip fabrication and manufacturing techniques developed for the electronics industry and highly suited for miniaturization and high throughput. 151-. (canceled)52. A method of nucleic acid sequencing comprising the steps of:providing an array of integrated analytical devices, each device comprising a nucleic acid template/polymerase primer complex immobilized within an optically confined region, a plurality of fluorescently labeled nucleotides in fluid contact with the nucleic acid template/polymerase primer complex, and a single detector element optically coupled to the optically confined region, wherein at least two fluorescently labeled nucleotides of the plurality of fluorescently labeled nucleotides emit fluorescence of different intensities at an emission wavelength;illuminating the optically confined region with an excitation wavelength;measuring a fluorescent signal from the optically confined region at the single detector element; andidentifying a least one of the at least two fluorescently labeled nucleotides by an intensity of the measured fluorescent signal at the emission wavelength.53. The method of claims 52 , wherein the array of integrated analytical devices comprises:a substrate layer, wherein the substrate layer is a detector layer;a waveguide module layer disposed above the substrate layer, wherein the waveguide module layer comprises a lower waveguide cladding material, a waveguide core material, and an upper waveguide cladding material; anda ...

DEVICE FOR FABRICATING OPTICAL FIBER BRAGG GRATING AND THE METHOD THEREOF

Provided are a device and method for fabricating an optical fiber Bragg grating, comprising a laser device, a laser shaping device, a laser interference device, a clamping movable device, and an organic-solution filling device; a liquid filling port of the clamping movable device is connected to the output port of the organic-solution filling device; the laser device emits laser light to the laser shaping device; the laser shaping device shapes the laser light, then transmits it to the laser interference device; the laser interference device splits the laser into two laser beams; the two laser beams interfere and periodically distributed laser interference fringes are obtained; the organic-solution filling device fills and attaches the organic solution to the surface of the inner wall of an hollow-core fiber; the clamping movable device moves the hollow-core fiber. 1. A device for preparing optical fiber Bragg grating , which comprises a laser device , a laser shaping device , a laser interference device , a clamping and moving device and organic solution filling device; wherein the clamping and moving device has a liquid filling port which is connected with an output port of the organic solution filling device; andthe laser device emits a laser to the laser shaping device, the laser shaping device performs a shaping process on the laser and emits a shaped laser to the laser interference device, the laser interference device divides the shaped laser into two laser beams and then interferes the two laser beams so as to obtain periodically distributed laser interference fringes, the organic solution filling device fills and attaches an organic solution onto an inner wall surface of a hollow-core optical fiber, and the clamping and moving device moves the hollow-core optical fiber with inner wall surface filled and attached with the organic solution to an area where the laser interference fringes are located and ensures that an air optical fiber core of the hollow-core ...

GRATING MANUFACTURING DEVICE AND GRATING MANUFACTURING METHOD

Provided are an apparatus for manufacturing a grating and a method for manufacturing a grating with which a grating having a desired attenuate wavelength characteristic can be easily manufactured. The apparatus, which forms a grating in an optical fiber as an optical waveguide, includes a laser source, beam diameter adjusting means, a scanning mirror, mirror position adjusting means, a cylindrical lens, lens position adjusting means, a phase mask, mask position adjusting means, a stage, a fixing jig, and a synchronous controller. The synchronous controller controls an adjustment of a position of the scanning mirror performed by the mirror position adjusting means and an adjustment of a position of the phase mask performed by the mask position adjusting means in a manner in which they are associated with each other. 1. An apparatus for manufacturing a grating that writes a grating in an optical waveguide , the apparatus comprising:a laser source that outputs laser light;mirror position adjusting means that is movable in an axial direction of the optical waveguide and that adjusts a position of a scanning mirror, which deflects the laser light to the optical waveguide, so as to adjust a grating write position in the optical waveguide;mask position adjusting means that adjusts a position of a phase mask, which is disposed between the scanning mirror and the optical waveguide, so as to adjust a distance between the phase mask and the optical waveguide; anda synchronous controller that controls an adjustment of the position of the scanning mirror performed by the mirror position adjusting means and an adjustment of the position of the phase mask performed by the mask position adjusting means in a manner in which the adjustment of the position of the scanning mirror and the adjustment of the position of the phase mask are associated with each other.2. The apparatus for manufacturing a grating according to claim 1 , further comprising:beam diameter adjusting means that is ...

MEDICAL LASER DEVICE AND RELATED METHODS

A laser delivery device may include a connector portion at a proximal end of the laser delivery device and an optical fiber connecting the connector portion to a distal end of the laser delivery device. The connector portion may include a capillary at least partially surrounding a proximal portion of the optical fiber, and the capillary may include dimples on at least a portion of a circumferential surface thereof. 120-. (canceled)21. A laser delivery device , comprising:an optical fiber, including a proximal portion and a distal portion; anda capillary surrounding at least a portion of the optical fiber and including a proximal portion and a distal portion,wherein the capillary includes a dimple free portion at the proximal portion and a dimpled portion.22. The laser delivery device of claim 21 , wherein the capillary is fused to the optical fiber at the proximal portion of the optical fiber.23. The laser delivery device of claim 22 , wherein the capillary is fused to the proximal portion of the optical fiber along the dimple free portion of the capillary.24. The laser delivery device of claim 21 , wherein the capillary is formed of glass.25. The laser delivery device of claim 21 , wherein the dimpled portion includes a plurality of circular dimples on at least a portion of an outer circumferential surface thereof.26. The laser delivery device of claim 25 , wherein the dimples are not included on the outer circumferential surface of the distal portion of the capillary.27. The laser delivery device of claim 25 , wherein the outer circumferential surface of the capillary includes projections.28. The laser delivery device of claim 25 , wherein the dimples are formed by melting with a COlaser in a pulsed mode claim 25 , and wherein the dimple free portion of the capillary is fused to the proximal end of the optical fiber with the COlaser.29. The laser delivery device of claim 21 , wherein the proximal portion of the optical fiber is configured to be coupled to a laser ...

OPTICAL DISPERSION COMPENSATOR ON SILICON

An optical dispersion compensator integrated with a silicon photonics system including a first phase-shifter coupled to a second phase-shifter in parallel on the silicon substrate characterized in an athermal condition. The dispersion compensator further includes a third phase-shifter on the silicon substrate to the first phase-shifter and the second phase-shifter through two 2×2 splitters to form an optical loop. A second entry port of a first 2×2 splitter is for coupling with an input fiber and a second exit port of a second 2×2 splitter is for coupling with an output fiber. The optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain wavelength in the input fiber is substantially compensated and independent of temperature. 1. An optical dispersion compensator comprising:a first phase-shifter;a second phase-shifter;a first 2×2 splitter having a first exit port coupled to an input port of the first phase-shifter and a second exit port coupled to an input port of the second phase-shifter;a second 2×2 splitter having a first entry port coupled to an output port of the first phase-shifter and a second entry port coupled to an output port of the second phase-shifter;a third phase-shifter on the silicon substrate having an input port coupled to a first exit port of the second 2×2 splitter and an output port coupled to a first entry port of the first 2×2 splitter to form an optical loop with the first phase-shifter and the second phase-shifter;wherein the second entry port of the first 2×2 splitter is configured as an external input and the second exit port of the second 2×2 splitter is configured as an external output, wherein the optical loop is characterized by a total phase delay tunable via each of the first phase-shifter, the second phase-shifter, and the third phase-shifter such that a normal dispersion (>0) at a certain ...

METHODS OF PRODUCING SLANTED GRATINGS WITH VARIABLE ETCH DEPTHS

Methods of producing gratings with trenches having variable height are provided. In one example, a method of forming a diffracted optical element may include providing an optical grating layer over a substrate, patterning a hardmask over the optical grating layer, and forming a sacrificial layer over the hardmask, the sacrificial layer having a non-uniform height measured from a top surface of the optical grating layer. The method may further include etching a plurality of angled trenches into the optical grating layer to form an optical grating, wherein a first depth of a first trench of the plurality of trenches is different than a second depth of a second trench of the plurality of trenches. 1. A method of forming a diffracted optical element , comprising:providing an optical grating layer; andetching a plurality of angled trenches into the optical grating layer to form an optical grating, wherein a first depth of a first trench of the plurality of trenches is different than a second depth of a second trench of the plurality of angled trenches, and wherein the etching comprises performing an angled ion etch at a non-zero angle with respect to a perpendicular to a plane defined by a top surface of the optical grating layer.2. The method of claim 1 , further comprising:providing the optical grating layer over a substrate;patterning a hardmask over the optical grating layer; andforming a sacrificial layer over the hardmask, the sacrificial layer having a non-uniform height measured from the top surface of the optical grating layer.3. The method of claim 2 , wherein forming the sacrificial layer comprises:depositing the sacrificial layer atop the hardmask; andetching the sacrificial layer to create a trench with a sloped bottom surface.4. The method of claim 3 , further comprising performing a vertical etch to form the trench.5. The method of claim 3 , further comprising:etching the optical grating layer to recess the trench into the optical grating layer;forming a ...

AN OVERLAPPED CHIRPED FIBER BRAGG GRATING SENSING FIBER AND METHODS AND APPARATUS FOR PARAMETER MEASUREMENT USING SAME

An optical sensor includes an optical fiber inscribed with a repeated refraction pattern such that light scattered from a location on the optical fiber is scattered at multiple frequencies in a range of frequencies. The inscribed patterns overlap at every measurement point along at least a portion of the length of the sensor. An optical sensing system including control circuitry coupled to the optical fiber detects measurement scatter data from the optical fiber over the range of frequencies, determines a change in the detected measurement scatter data over the range of frequencies, and extracts a parameter describing a state of the optical fiber from the determined change in the detected measurement scatter data. The sensor may be made by inscribing a first light refracting pattern on the optical fiber at every measurement point along at least a portion of the length of the sensor and inscribing a second light refracting pattern on the optical fiber that overlaps the first inscribed light refracting pattern at every measurement point along at least that portion of the length of the sensor. 1. An optical sensor comprising:an optical fiber inscribed with a repeated refraction pattern at multiple locations along the optical fiber such that light reflected from a location on the optical fiber is reflected at multiple frequencies in a range of frequencies,wherein at least two of the inscribed repeated refraction patterns overlap at every measurement point along at least a portion of the length of the sensor.2. The optical sensor in claim 1 , wherein the pattern includes overlapping chirped frequency fiber Bragg gratings.3. The optical sensor in claim 1 , wherein at least two of the refraction patterns overlap at every point along the entire length of the sensor.4. The optical sensor in claim 1 , further comprising multiple optical light guiding cores within the optical fiber claim 1 , each of the multiple optical light guiding cores being inscribed with the repeated ...

Narrow bandwidth reflectors for reducing stimulated brillouin scattering in optical cavities

An optical-fiber filter system to narrow a linewidth and to reduce noise fluctuations of an optical beam is provided. The optical-fiber filter system includes an optical fiber having a first end-face and an opposing second end-face, the first end-face and the second end-face setting a fiber length; a fiber Bragg grating having a first reflectivity positioned at the first end-face; and a reflector having a second reflectivity positioned at the second end-face. When the optical beam at a first frequency is coupled from a laser into one of the first end-face or the second end-face, a resonant cavity is established at the first frequency between the fiber Bragg grating and the reflector while Brillouin scattered light shifted from the first frequency within the optical fiber is transmitted through the fiber Bragg grating.

Communication apparatus

A communication apparatus includes an optical fiber along which radiation can be transmitted; an optical fiber grating formed within the optical fiber, the optical fiber grating having a structure, and configured to reflect radiation at a particular wavelength; and an instrument coupled to the grating and configured to controllably modify the structure of the grating, thereby changing the wavelength at which the grating reflects radiation. A communication system including the communication apparatus is also described, along with a method of communicating a signal.

OPTICAL FIBER SECURING STRUCTURE AND LASER DEVICE

An optical fiber securing structure includes: an optical fiber including a coating, and a coating-removed section in which a partial section of the coating is removed from the optical fiber; a reinforcement member including main surfaces and a groove formed from one of the main surfaces toward an inside of the reinforcement member, where the groove has a pair of side walls and a bottom wall; and a resin member that secures the coating-removed section to the pair of side walls and the bottom wall. A bottom part of the groove that includes the bottom wall has a widthwise cross-sectional shape where the bottom wall constitutes a trapezoidal shape such that a distance between the pair of side walls becomes greater in a direction away from the bottom wall. 1. An optical fiber securing structure comprising: a coating; and', 'a coating-removed section in which a partial section of the coating is removed from the optical fiber;, 'an optical fiber including main surfaces; and', 'a groove formed from one of the main surfaces toward an inside of the reinforcement member, where the groove has a pair of side walls and a bottom wall; and, 'a reinforcement member includinga resin member that secures the coating-removed section to the pair of side walls and the bottom wall, whereina bottom part of the groove that includes the bottom wall has a widthwise cross-sectional shape where the bottom wall constitutes a trapezoidal shape such that a distance between the pair of side walls becomes greater in a direction away from the bottom wall.2. The optical fiber securing structure as set forth in claim 1 , wherein the distance between the pair of side walls becomes greater in the direction away from the bottom wall.3. The optical fiber securing structure as set forth in claim 1 , whereina first inclination angle is formed between a normal to the one of the main surfaces and one of the pair of side walls,a second inclination angle is formed between the normal to the one of the main ...

FIBER OPTIC CONNECTOR ASSEMBLY WITH IN-LINE SPLITTER

A fiber optic connector assembly having a body connected to first and second tubular enclosures at their first ends is disclosed. The first tubular enclosure extends in a first direction. The second tubular enclosure extends in a second direction. An optical splitter is positioned in the body proximal to the first ends of the first tubular enclosure and the second tubular enclosure. A first waveguide extends from the optical splitter in the first direction through the first tubular enclosure. A second waveguide extends from the optical splitter in the second direction through the second tubular enclosure. A first fiber connector in optical communication with the first waveguide is connected to a second end of the first tubular enclosure. A second fiber connector in optical communication with the second waveguide and is connected to a second end of the second tubular enclosure. In some embodiments, the body may be sealed from environmental elements. 1. A fiber optic connector assembly , comprising:a body;a first tubular enclosure having a first end and a second end and connected to the body adjacent to the first end of the first tubular enclosure, and extended in a first direction;a second tubular enclosure having a first end and a second end and connected to the body adjacent to the first end of the second tubular enclosure, and extended in a second direction;an optical splitter positioned in the body proximal to the first end of the first tubular enclosure and the first end of the second tubular enclosure;a first waveguide extended from the optical splitter in the first direction through the first tubular enclosure;a second waveguide extended from the optical splitter in the second direction through the second tubular enclosure;a first fiber connector in optical communication with the first waveguide and connected adjacent to the second end of the first tubular enclosure; anda second fiber connector in optical communication with the second waveguide and connected ...

FIBER OPTIC CONNECTION DEVICE WITH AN IN-LINE SPLITTER

A fiber optic connection device having a casing with a first end and a second end is disclosed. An optical splitter is positioned in the casing and has an input proximal to the first end of the casing and an output proximal to the second end of the casing. A first optical interface is located adjacent to the first end and is in optical communication with the input of the optical splitter. The first optical interface includes a first optical fiber interconnection point. A second optical interface is located adjacent the second end of the casing and is in optical communication with the output of the optical splitter. The second optical interface includes a second optical fiber interconnection point. In some embodiments, the casing may provide protection from environmental elements. 1. A fiber optic device , comprising:a casing having a first end and a second end;an optical splitter positioned in the casing and having an input proximal to the first end and an output proximal to the second end;a first optical interface located adjacent the first end and in optical communication with the input of the optical splitter, wherein the first optical interface comprises a first optical fiber interconnection point; anda second optical interface located adjacent the second end and in optical communication with the output of the optical splitter, wherein the second optical interface comprises a second optical fiber interconnection point.2. The fiber optic device of claim 1 , wherein the first optical interface is in-line with the second optical interface and face in opposite directions.3. The fiber optic device of claim 1 , wherein the casing is sealed by overmold construction.4. The fiber optic device of claim 1 , wherein the casing is sealed by a potting material disposed in the casing.5. The fiber optic device of claim 1 , wherein the fiber optic connection device is sealed by a heat-shrink material applied over the casing.6. The fiber optic device of claim 1 , wherein the ...

USE OF VARIABLE BEAM PARAMETERS TO CONTROL SOLIDIFICATION OF A MATERIAL

A method for forming an article includes providing a material having a first material property; forming a melt pool by exposing the material to an optical beam having at least one beam characteristic, wherein the melt pool has at least one melt pool property determinative of a second material property of the material; and modifying the at least one beam characteristic in response to a change in the melt pool property. 1. A method for forming an article , comprising:providing a material comprising a first material property;forming a melt pool by exposing the material to an optical beam comprising at least one beam characteristic, wherein the melt pool comprises at least one melt pool property determinative of a second material property of the material; andmodifying the at least one beam characteristic in response to a change in the melt pool property.2. The method of claim 1 , further comprising:generating the optical beam in an optical beam delivery device comprising a first length of fiber having a first refractive-index profile (RIP) and a second length of fiber having a second RIP and being coupled to the first length of fiber, and a perturbation device configured to alter a bend radius of the first length of fiber;launching the optical beam into the first length of fiber; andcoupling the optical beam into the second length of fiber, activating the perturbation device to modify one or more beam characteristics of the optical beam in one or more of the first length of fiber and the second length of fiber, and', 'confining at least a portion of the modified one or more beam characteristics of the optical beam within one or more confinement regions of the second length of fiber,, 'wherein modifying of the at least one beam characteristic comprises'}wherein the first RIP differs from the second RIP.3. The laser-melting method of claim 1 , wherein the modifying of the at least one beam characteristic of the optical beam occurs prior to or during the exposing of the ...

Method of making optical fibers in a reducing atmosphere

A method for forming an optical fiber preform and fibers drawn from the preform. The method includes forming a soot cladding monolith, inserting a consolidated core cane into the internal cavity, and processing the resulting core-cladding assembly to form a preform. Processing may include exposing the core-cladding assembly to a drying agent and/or dopant precursor, and sintering the core-cladding assembly in the presence of a reducing agent to densify the soot cladding monolith onto the core cane to form a preform. The preform features low hydroxyl content and low sensitivity to hydrogen. Fibers drawn from the preform exhibit low attenuation losses from absorption by the broad band centered near 1380 nm.

WRITING OF HIGH MECHANICAL STRENGTH FIBER BRAGG GRATINGS USING ULTRAFAST PULSES AND A PHASE MASK

An optical fiber having a Bragg grating along a non-photosensitized grating region thereof and a pristine polymer coating around the grating region with the Bragg grating having been written through the polymer coating has a mechanical resistance that is greater than 20% of the mechanical resistance of an identical grating-free optical fiber.” 124-. (canceled)25. A manufacture comprising an optical fiber , wherein said optical fiber comprises a Bragg grating along a non-photosensitized grating region thereof , wherein said optical fiber has a pristine polymer coating around said grating region , wherein said Bragg grating has been written through said polymer coating , wherein said optical fiber is characterized by a mechanical resistance that is greater than 20% of a mechanical resistance of an identical grating-free optical fiber.26. The manufacture of claim 25 , wherein said Bragg grating is characterized by a fundamental Bragg resonance.27. The manufacture of claim 25 , wherein said optical fiber comprises a core and a cladding claim 25 , wherein said non-photosensitized grating region is provided within said core claim 25 , wherein said cladding surrounds said core claim 25 , and wherein said polymer coating extends around said cladding.28. The manufacture of claim 26 , wherein said core and said cladding are made of a glass material or of a crystalline material.29. The manufacture of claim 25 , wherein said Bragg grating defines a refractive index modulation greater than 5.10.30. The manufacture of claim 25 , wherein said optical fiber has a mechanical resistance of at least 99% of said mechanical resistance of an identical grating-free optical fiber.31. The manufacture of claim 25 , further comprising a wavelength-division-multiplexing light filter claim 25 , wherein said optical fiber is a constituent of said wavelength-division-multiplexing light filter.32. The manufacture of claim 25 , further comprising a laser having a laser cavity claim 25 , wherein ...

Methods and apparatus for determining shape parameter(s) using a sensing fiber having a single core with multiple light propagating modes

Example embodiments include an optical interrogation system with a sensing fiber having a single core, the single core having multiple light propagating modes. Interferometric apparatus probes the single core multimode sensing fiber over a range of predetermined wavelengths and detects measurement interferometric data associated with the multiple light propagating modes of the single core for each predetermined wavelength in the range. Data processing circuitry processes the measurement interferometric data associated with the multiple light propagating modes of the single core to determine one or more shape-sensing parameters of the sensing fiber from which the shape of the fiber in three dimensions can be determined.

Methods and devices for optoacoustic stimulation

A tapered fiber optoacoustic emitter includes a nanosecond laser configured to emit laser pulses and an optic fiber. The optic fiber includes a tip configured to guide the laser pulses. The tip has a coating including a diffusion layer and a thermal expansion layer, wherein the diffusion layer includes epoxy and zinc oxide nanoparticles configured to diffuse the light while restricting localized heating. The thermal expansion layer includes carbon nanotubes (CNTs) and Polydimethylsiloxane (PDMS) configured to convert the laser pulses to generate ultrasound. The frequency of the ultrasound is tuned with a thickness of the diffusion layer and a CNT concentration of the expansion layer.

Index matched grating inscription

The disclosed embodiments provide systems and methods for mitigating lensing and scattering as an optical fiber is being inscribed with a grating. The disclosed systems and methods mitigate the lensing phenomenon by surrounding an optical fiber with an index-matching material that is held in a vessel with an integrated interferometer (e.g., phase mask, etc.). The index-matching material has a refractive index that is sufficient to reduce intensity variations of the actinic radiation within the optical fiber. Some embodiments of the system include different vessels for holding the index-matching material, with the vessel having an interferometer integrated into the vessel. These vessels permit the optical fiber to be surrounded by the index-matching material while the gratings are written to the optical fiber.

INDEX MATCHED GRATING INSCRIPTION

The disclosed embodiments provide systems and methods for mitigating lensing and scattering as an optical fiber is being inscribed with a grating. The disclosed systems and methods mitigate the lensing phenomenon by surrounding an optical fiber with a liquid index-matching material that is held in a vessel. The disclosed systems also include a replenishment mechanism that replenishes the liquid index-matching material as the optical fiber is pulled through the vessel. 1. A system for writing a grating onto an optical fiber , the system comprising: a passage through which the optical fiber is pulled, the passage to surround the optical fiber with the liquid index-matching material, the optical fiber being coated by the liquid index-matching material as it is pulled through the passage;', 'an entry through which the optical fiber enters the passage; and', 'an exit through which the optical fiber coated with the liquid index-matching material exits the passage;, 'a vessel to hold a liquid index-matching material, the liquid index-matching material adhering to the optical fiber, the vessel comprisinga reel-to-reel system operatively coupled to the vessel, the reel-to-reel system to pull the optical fiber through the passage;a replenishment system operatively coupled to the vessel, the replenishment system to replenish the vessel with liquid index-matching material; andan exit cleaning system located at the exit, the exit cleaning system to remove the coated liquid index-matching material from the optical fiber as the optical fiber exits the passage.2. The system of claim 3 , further comprising an entry cleaning system located at the entry claim 3 , the entry cleaning system to clean the optical fiber before the optical fiber enters the passage.3. A system claim 3 , comprising:a vessel to hold a liquid index-matching material, the vessel comprising a passage for an optical fiber such that the optical fiber is surrounded by the liquid index-matching material;an index- ...

INDEX MATCHED GRATING INSCRIPTION

The disclosed embodiments provide systems and methods for mitigating lensing and scattering as an optical fiber is being inscribed with a grating. The disclosed systems and methods mitigate the lensing phenomenon by surrounding an optical fiber with an index-matching material that is held in a vessel with an integrated interferometer (e.g., phase mask, etc.). The index-matching material has a refractive index that is sufficient to reduce intensity variations of the actinic radiation within the optical fiber. Some embodiments of the system include different vessels for holding the index-matching material, with the vessel having an interferometer integrated into the vessel. These vessels permit the optical fiber to be surrounded by the index-matching material while the gratings are written to the optical fiber. 1. A system , comprising:a liquid index-matching material having an index of refraction that substantially matches a refractive index of an optical fiber; and a back plate;', 'a mask to generate an interference pattern from incoming ultraviolet (UV) radiation; and', 'a gap separating the back plate and the mask, the gap to hold the liquid index-matching material, the gap forming a passage for the optical fiber such that the optical fiber is surrounded by the liquid index-matching material., 'a vessel, comprising2. The system of claim 1 , the mask being a phase mask.3. The system of claim 1 , the mask being an amplitude mask.4. The system of claim 1 , the index-matching material having an index of refraction that minimizes an intensity variation within an irradiated cross-section of the optical fiber.5. A system claim 1 , comprising:an index-matching material having a refractive index that substantially matches a refractive index of an optical fiber;a vessel to hold the index-matching material, the vessel comprising a passage for the optical fiber such that the optical fiber is surrounded by the index-matching material; anda mask integrated with the vessel, the ...

ARRAYS OF INTEGRATED ANALYTICAL DEVICES AND METHODS FOR PRODUCTION

Arrays of integrated analytical devices and their methods for production are provided. The arrays are useful in the analysis of highly multiplexed optical reactions in large numbers at high densities, including biochemical reactions, such as nucleic acid sequencing reactions. The integrated devices allow the highly sensitive discrimination of optical signals using features such as spectra, amplitude, and time resolution, or combinations thereof. The arrays and methods of the invention make use of silicon chip fabrication and manufacturing techniques developed for the electronics industry and highly suited for miniaturization and high throughput. 151-. (canceled)52. An array of integrated analytical devices comprising:a substrate layer, wherein the substrate layer is a detector layer;a waveguide module layer disposed above the substrate layer, wherein the waveguide module layer comprises a lower waveguide cladding material, a waveguide core material, and an upper waveguide cladding material; anda zero-mode waveguide module layer disposed on the waveguide module layer, wherein the zero-mode waveguide module layer comprises a plurality of nanometer-scale apertures penetrating to the waveguide module layer;wherein at least one analytical device comprises a single detector element in the detector layer, and wherein the single detector element is optically coupled to a single nanometer-scale aperture through the waveguide module layer.53. The array of claim 52 , wherein the detector layer is a CMOS wafer.54. The array of claim 52 , wherein the single detector element comprises one pixel.55. The array of claim 52 , wherein the array does not comprise a color separation layer.56. The array of claim 52 , wherein the upper waveguide cladding material is SiO.57. The array of claim 52 , wherein the waveguide core material is SiN.58. The array of claim 52 , wherein at least one of the plurality of nanometer-scale apertures comprises a fluid sample comprising a fluorescent ...

OPTIMIZED OPTICAL FIBER FOR ENHANCED SCATTER IN DOWNHOLE ENVIRONMENTS

An apparatus for sensing a value of a property in a borehole having hydrogen gas penetrating a subsurface formation includes an optical fiber configured to be disposed in the borehole having the hydrogen gas and comprising a core having a fiber Bragg grating that is responsive to the value of the property and a cladding disposed about the core, wherein (i) the core is doped with a first dopant that is photo-sensitive for writing the fiber Bragg grating and that has a concentration in the core of 2 Mole % or less and (ii) the cladding is doped with a second dopant that lowers an index of refraction of the cladding. 1. An apparatus for sensing a value of a property in a borehole having hydrogen gas penetrating a subsurface formation , the apparatus comprising:an optical fiber configured to be disposed in the borehole having the hydrogen gas and comprising a core having a fiber Bragg grating that is responsive to the value of the property and a cladding disposed about the core, wherein (i) the core is doped with a first dopant that is photo-sensitive for writing the fiber Bragg grating and that has a concentration in the core of 2 Mole % or less and (ii) the cladding is doped with a second dopant that lowers an index of refraction of the cladding.2. The apparatus according to claim 1 , wherein the first dopant is at least one of Germanium claim 1 , Phosphorous claim 1 , and Aluminum.3. The apparatus according to claim 1 , wherein the second dopant is at least one of Fluorine and Boron.4. The apparatus according to claim 1 , wherein a numerical aperture of the optical fiber is in a range of 0.10 to less than 0.14.5. The apparatus according to claim 1 , wherein light scattering of the fiber Bragg grating is in a range of −70 db/mm to less than −50 db/mm.6. The apparatus according to claim 5 , wherein the light scattering of the fiber Bragg grating is 20 db/mm greater than natural light scattering from the optical fiber without the fiber Bragg grating.7. The apparatus ...

APPARATUS FOR OPTICAL APPLICATIONS, SPECTROMETER SYSTEM AND METHOD FOR PRODUCING AN APPARATUS FOR OPTICAL APPLICATIONS

The present invention relates to an apparatus for optical applications, a spectrometer system and method for producing an apparatus for optical applications, and in particular to an apparatus comprising an optical waveguide having a first refractive index along a light propagation axis interrupted by a plurality of scattering portions having a second refractive index. Each scattering portion has a long axis substantially perpendicular to the light propagation axis as well as a short axis substantially perpendicular to the light propagation axis and the long axis. A receiver unit or a transmitter unit is arranged on a side of the optical waveguide, the long axis being substantially perpendicular, i.e. normal to the plane of this side on which the receiver unit or transmitter unit is arranged. Accordingly, simplification and miniaturization of an optical apparatus can be realized. 114.-. (canceled)15. An apparatus for optical applications , comprising:an optical waveguide configured to guide light along a light propagation axis and having a first refractive index along the light propagation axis interrupted by a plurality of portions having a second refractive index, wherein each portion of the plurality of portions has a long axis perpendicular to the light propagation axis and a short axis perpendicular to the light propagation axis and the long axis, the short axis being shorter than the long axis; anda receiver arranged on a side of the optical waveguide,wherein the receiver is arranged so as to receive light scattered from the plurality of portions.16. The apparatus for optical applications according to claim 15 , wherein the receiver comprises optical detectors arranged in a line for detecting the light scattered from the plurality of portions claim 15 , the line of the optical detectors being parallel to the light propagation axis.17. A spectrometer system claim 16 , comprising a light source and the apparatus according to claim 16 , wherein light of the light ...

METHOD OF FABRICATING A FIBRE DEVICE

Various embodiments provide a method of fabricating a fibre, the method comprising translating a fibre having a light transmissive core surrounding by a cladding material; and while translating, non-interferometrically applying energy to alter structure of the light transmissive core and/or the cladding material. 1. A method of fabricating a fibre device; the method comprising:translating a fibre having a light transmissive core surrounding by a cladding material; and,while translating, non-interferometrically applying energy to alter structure of the light transmissive core and/or the cladding material.2. The method according to claim 1 , wherein the step of applying energy further comprises applying a pulse light.3. The method according to claim 1 , wherein the step of applying energy further comprises applying a focused light.4. The method according to claim 1 , wherein the structure of the core is altered to alter properties of a light transmitting the core.5. The method according to claim 4 , wherein altering the properties of the light includes at least one of removing a wavelength of the light claim 4 , polarizing the light and filtering the light.6. The method according to claim 1 , wherein the structure of the light transmissive core is altered to sense temperature.7. The method according to claim 1 , wherein the structure of the light transmissive core is altered to sense pressure.8. The method according to claim 7 , wherein the structure of the light transmissive core is altered at least twice to sense airflow.9. The method according to claim 1 , wherein the structure of the light transmissive core is altered to control polarization.10. The method according to claim 1 , wherein the step of applying energy to alter structure of the light transmissive core includes altering a refractive index of the core so as to alter an index profile.11. The method according to claim 1 , wherein the step of translating the fibre includes inscribing at least one grating in ...

Photonic Apparatus for Controlling Polarization

A polarization-sensitive photonic splitter may include a lower cladding layer and a device layer formed from a first waveguide supporting TE and TM light, a second waveguide, a third waveguide, and a transition core. The first waveguide core and the second waveguide core are formed from one of a first core structure or a second core structure, and the third waveguide is formed from the other structure. The first core structure has an index of refraction n. The second core structure is formed as alternating layers providing an effective index of refraction for TE light nand an effective index of refraction for TM light n, where n Подробнее

Photonic Apparatus for Controlling Polarization

A photonic device may include a lower cladding layer and a device layer. The device layer may include a first waveguide supporting TE and TM light, and a second waveguide, where a portion of a second waveguide core is proximate to a first waveguide core to provide evanescent coupling. The first waveguide core is formed from one of a first core structure or a second core structure, and the second waveguide core is formed from the other structure. The first core structure has an index of refraction n. The second core structure is formed as alternating layers providing an effective index of refraction for TE polarized light nand an effective index of refraction for TM polarized light n, where n Подробнее

OPTICAL FIBER AND SLANTED FIBER GRATING

An optical fiber is made of silica-based glass and includes a core, a first cladding that surrounds the core and that has a refractive index lower than a refractive index of the core; and a second cladding that surrounds the first cladding and that has a refractive index lower than the refractive index of the core and higher than the refractive index of the first cladding. At least a part of the first cladding contains a photosensitive material whose refractive index increases by irradiation with light having a specific wavelength. A difference Δn between a refractive index of a portion of the first cladding, the portion being nearest to the core, and the refractive index of the core is in a range of 0.25% to 0.30%. The radius ra of the core is larger than 4.3 μm and smaller than or equal to 5.0 μm. 1. An optical fiber made of silica-based glass , comprising:a core that includes a central axis of the optical fiber and that has a radius ra that is larger than 4.3 μm and smaller than or equal to 5.0 μm;a first cladding that is in contact with the core, that surrounds the core, that has an outer radius rb, and that has a refractive index lower than a refractive index of the core; anda second cladding that is in contact with the first cladding, that surrounds the first cladding, and that has a refractive index lower than the refractive index of the core and higher than the refractive index of the first cladding,wherein at least a part of the first cladding contains a photosensitive material whose refractive index increases by irradiation with light,wherein, at the radius ra, a gradient of a refractive index in a direction away from the central axis along a straight line perpendicular to the central axis is negative and maximum, andwherein, in a graph in which the straight line perpendicular to the central axis is a horizontal axis and the refractive index is a vertical axis, a difference between a value that an extension of a straight line connecting a refractive index ...

BIREFRINGENT MULTI-PEAK OPTICAL REFERENCE ELEMENT AND BIREFRINGENT SENSOR SYSTEM

Certain aspects of the present disclosure generally relate to an optical reference element having a wavelength spectrum comprising a plurality of wavelength functions having wavelength peaks spaced over a range of wavelengths, wherein adjacent wavelength functions are due to two orthogonal birefringence axes in the optical reference element. Aspects of the present disclosure may eliminate the drift issues associated with residual polarization and polarization dependent loss (PDL) with respect to grating-based sensor and reference element measurements. 1. A reference optical sensor comprising a core with a modulated refractive index , wherein:in response to light introduced into the reference optical sensor, the modulated refractive index is configured to produce a wavelength spectrum comprising multiple pairs of wavelength functions having wavelength peaks spaced over a range of wavelengths; andadjacent wavelength functions in each pair are due to two orthogonal birefringence axes in the reference optical sensor.2. The reference optical sensor of claim 1 , wherein the wavelength peaks are uniformly spaced over at least a portion of the range of wavelengths at a particular temperature and pressure.3. The reference optical sensor of claim 1 , wherein edges of the adjacent wavelength functions do not significantly overlap.4. The reference optical sensor of claim 1 , wherein the adjacent wavelength functions are distinguishable over a range of environmental operating conditions for the reference optical sensor.5. The reference optical sensor of claim 1 , further comprising:a stress feature configured to generate the two orthogonal birefringence axes for light propagated in the core; anda cladding surrounding the core and the stress feature.6. The reference optical sensor of claim 5 , wherein an outer diameter of the cladding is at least 0.3 mm.7. The reference optical sensor of claim 5 , wherein the stress feature has an elliptical shape in cross-section.8. The ...

EDGE SEALANT CONFINEMENT AND HALO REDUCTION FOR OPTICAL DEVICES

Techniques are described for using confinement structures and/or pattern gratings to reduce or prevent the wicking of sealant polymer (e.g., glue) into the optically active areas of a multi-layered optical assembly. A multi-layered optical structure may include multiple layers of substrate imprinted with waveguide grating patterns. The multiple layers may be secured using an edge adhesive, such as a resin, epoxy, glue, and so forth. A confinement structure such as an edge pattern may be imprinted along the edge of each layer to control and confine the capillary flow of the edge adhesive and prevent the edge adhesive from wicking into the functional waveguide grating patterns of the layers. Moreover, the edge adhesive may be carbon doped or otherwise blackened to reduce the reflection of light off the edge back into the interior of the layer, thus improving the optical function of the assembly. 1. An optical structure comprising: a first grating pattern forming an optically functional region of the substrate; and', 'a second grating pattern on the substrate and proximal to an edge of the substrate, the second grating pattern arranged to control capillary flow of a material from the edge of the substrate into the second grating pattern and inhibit the capillary flow of the material into the optically functional region of the substrate., 'a substrate including2. The optical structure of claim 1 , wherein:the first grating pattern is on a first surface of the substrate; andthe second grating pattern is on a second surface of the substrate.3. The optical structure of claim 1 , wherein the first grating pattern and the second grating pattern are on a first surface of the substrate.4. The optical structure of claim 1 , wherein the substrate further includes a third grating forming a second optically functional region of the substrate.5. The optical structure of claim 1 , wherein the optically functional region of the substrate includes one or more of an orthogonal pupil ...

METHOD OF LASER MODIFICATION OF AN OTPICAL FIBRE

Method of laser modifying an optical fibre to form a modified region at a target location within the fibre, comprising positioning at least a portion of an optical fibre in a laser system for modification by a laser, applying a correction to an active optical element of the laser system to modify wavefront properties of the laser to counteract an effect of aberration on laser focus, and laser modifying the optical fibre at the target location using the laser with the corrected wavefront properties to produce the modified region. 1. A method of laser modifying an optical fibre to form a modified region at a target location within the fibre , comprising:positioning at least a portion of an optical fibre in a laser system for modification by a laser;applying a correction to an active optical element of the laser system to modify wavefront properties of the laser to counteract an effect of aberration on laser focus; andlaser modifying the optical fibre at the target location using the laser with the corrected wavefront properties to produce the modified region.2. A method as claimed in claim 1 , comprising determining the correction to be applied to the active optical element based at least upon characteristics of the optical fibre.3. A method as claimed in claim 2 , wherein the step of determining the correction comprises determining the correction based upon the position of the target location within the fibre.4. A method as claimed in any preceding claim wherein the step of applying the correction to the active optical element comprises applying the correction to the active optical element to modify wavefront properties of the laser to counteract an effect of astigmatic aberration on laser focus.5. A method as claimed in any preceding claim claim 2 , wherein the step of applying the correction to the active optical element comprises applying the correction to the active optical element to modify wavefront properties of the laser to counteract an effect of spherical ...

Light detecting device and optical system including the same

Provided is a light detecting device including a light input device configured to receive light, a plurality of waveguides extending from the light input device, the plurality of waveguides being configured to transmit portions of the light received by the light input device, respectively, a plurality of modulators provided on the plurality of waveguides and configured to modulate phases of the portions of light transmitted in the plurality of waveguides, respectively, at least one graphene layer configured to absorb the portions of light transmitted in the plurality of waveguides, and at least one first electrode and at least one second electrode electrically connected to the at least one graphene layer, respectively.

USE OF VARIABLE BEAM PARAMETERS TO CONTROL SOLIDIFICATION OF A MATERIAL

A method for forming an article includes providing a material having a first material property; forming a melt pool by exposing the material to an optical beam having at least one beam characteristic, wherein the melt pool has at least one melt pool property determinative of a second material property of the material; and modifying the at least one beam characteristic in response to a change in the melt pool property. 1. A method for forming an article , comprising:providing a material comprising a first material property;forming a melt pool by exposing the material to an optical beam comprising at least one beam characteristic, wherein the melt pool comprises at least one melt pool property determinative of a second material property of the material; andmodifying the at least one beam characteristic in response to a change in the melt pool property.2. The method of claim 1 , further comprising:generating the optical beam in an optical beam delivery device comprising a first length of fiber having a first refractive-index profile (RIP) and a second length of fiber having a second RIP and being coupled to the first length of fiber, and a perturbation device configured to alter a bend radius of the first length of fiber;launching the optical beam into the first length of fiber; andcoupling the optical beam into the second length of fiber, activating the perturbation device to modify one or more beam characteristics of the optical beam in one or more of the first length of fiber and the second length of fiber, and', 'confining at least a portion of the modified one or more beam characteristics of the optical beam within one or more confinement regions of the second length of fiber,, 'wherein modifying of the at least one beam characteristic comprises'}wherein the first RIP differs from the second RIP.3. The laser-melting method of claim 1 , wherein the modifying of the at least one beam characteristic of the optical beam occurs prior to or during the exposing of the ...

Methods of and systems for heat deposition in additive manufacturing

An apparatus for heat deposition in additive manufacturing may include: a first optical beam source configured to generate a first optical beam; a second optical beam source configured to generate a second optical beam; and/or an optical system. The optical system may be configured to move the generated first optical beam over a target area. The optical system may be further configured to move the generated second optical beam over the target area so that a path of the second optical beam moving over the target area is dithered about a path of the first optical beam moving over the target area. The optical system may be configured to focus the generated first optical beam at a plane of a target area. The optical system may be further configured to focus the generated second optical beam at the plane of the target area.

MICROHEATER COMPRISING A RARE EARTH-DOPED OPTICAL FIBER

A microheater comprises an optical fiber including a rare earth-doped glass core surrounded by a glass cladding. The rare earth-doped glass core comprises a rare earth dopant at a concentration sufficient for luminescence quenching such that, when the rare earth dopant is pumped with light at an absorption band wavelength, at least about 90% of absorbed pump light is converted into heat. 1. A microheater comprising:an optical fiber comprising a rare earth-doped glass core surrounded by a glass cladding, the rare earth-doped glass core comprising a rare earth dopant at a concentration sufficient for luminescence quenching such that, when the rare earth dopant is pumped with light at an absorption band wavelength, at least about 90% of absorbed pump light is converted into heat.2. The microheater of claim 1 , wherein the rare earth dopant comprises a rare earth species selected from the group consisting of: cerium claim 1 , dysprosium claim 1 , erbium claim 1 , europium claim 1 , holmium claim 1 , neodymium claim 1 , praseodymium claim 1 , samarium claim 1 , terbium claim 1 , thulium claim 1 , and ytterbium.3. The microheater of claim 2 , wherein the rare earth dopant comprises a compound comprising the rare earth species claim 2 , the compound being selected from the group consisting of: a rare earth oxide claim 2 , a rare earth fluoride claim 2 , a rare earth phosphate claim 2 , a rare earth borate claim 2 , and a rare earth chalcogenide.4. The microheater of claim 1 , wherein the concentration of the rare earth dopant is at least about 5 wt. %.5. The microheater of claim 1 , wherein the rare earth-doped glass core further comprises an additional dopant comprising OH— or a transition metal to facilitate thermal energy generation through non-radiative decay.6. The microheater of claim 1 , wherein the rare earth-doped glass core and the glass cladding comprise a glass selected from the group consisting of: a silicate glass claim 1 , a fluoride glass claim 1 , a ...

FORMING AN OPTICAL GRATING WITH AN APPARATUS PROVIDING AN ADJUSTABLE INTERFERENCE PATTERN

An apparatus for use with a pulsed laser source for forming an optical grating in a target includes an adjustable telescope having an element with a negative optical power, for generation of a diverging optical beam, so that the optical beam has adjustable divergence upon exiting the telescope while focusing of light inside the telescope is avoided. A transmission diffraction grating is disposed in the optical beam exiting the telescope, for forming an optical interference pattern on the target. Optical gratings with different grating periods may be formed by adjusting the divergence of the optical beam exiting the telescope. Lack of tight focal spots inside the telescope enables use of ultrashort pulse duration, high peak intensity laser sources. 1. An apparatus for forming an optical grating in a target extending in a first direction , the apparatus comprising:a telescope comprising:a first optical element having negative optical power in a first plane including the first direction, for receiving a first optical beam and for forming a diverging optical beam therefrom; anda second optical element having positive optical power in the first plane, disposed downstream of the first optical element, for receiving the diverging optical beam and for forming a second optical beam therefrom;a telescope support for supporting the first and second optical elements, the telescope support comprising a movable portion for adjusting a divergence of the second optical beam by adjusting a distance between the first and second optical elements; anda transmission diffraction grating disposed downstream of the telescope, for receiving the second optical beam and for splitting the second optical beam into first and second sub-beams;wherein in operation, when the first optical beam is received by the first optical element, the first and second sub-beams overlap on the target and form an optical interference pattern on the target for forming the optical grating therein, wherein the ...

OPTICAL FIBER RIBBON IMAGING GUIDEWIRE AND METHODS

An intravascular or other 2D or 3D imaging apparatus can include a minimally-invasive distal imaging guidewire portion. A plurality of thin optical fibers can be circumferentially distributed about a cylindrical guidewire core, such as in an spiral-wound or otherwise attached optical fiber ribbon. A low refractive index coating, high numerical aperture (NA) fiber, or other technique can be used to overcome challenges of using extremely thin optical fibers. Coating and ribbonizing techniques are described. Also described are non-uniform refractive index peak amplitudes or wavelengths techniques for FBG writing, using a depressed index optical cladding, chirping, a self-aligned connector, optical fiber routing and alignment techniques for a system connector, and an adapter for connecting to standard optical fiber coupling connectors. 1. (canceled)2. An apparatus for imaging a vascular system of a human body , the apparatus comprising:an elongated intravascular central core member sized, shaped, or otherwise configured to be inserted into the vascular system, the central core member having an outer surface;an optical fiber ribbon, including a plurality of optical fibers extending along the optical fiber ribbon, the optical fiber ribbon affixed to the central core member, wherein the optical fiber ribbon is wound about a circumference of the outer surface of the central core member and attached to the central core member,wherein at least one of the optical fibers is coated with an optical fiber coating having an index of refraction of less than or equal to 1.46.3. The apparatus of claim 2 , wherein the optical fiber has an outer diameter between about 25 micrometers and about 30 micrometers.4. The apparatus of claim 2 , wherein the central core member with the optical fiber ribbon wound about and attached thereto are cut together to provide mating first and second ends.5. The apparatus of claim 2 , wherein at least one of the optical fibers is photosensitive enough to ...

Multi-parameter Sensing based on Few-mode Fiber Bragg Gratings using Femtosecond IR Laser

A sensor system includes a femtosecond infrared (fs-IR) laser to generate a laser beam; a reflecting mirror optically receiving the laser beam; a lens optically coupled to the reflecting mirror to focus the laser beam; a phase mask receiving the laser beam from the lens to generate an index modulated pattern; and a few-mode fiber (FMF) receiving the index modulated pattern.

BIREFRINGENT MULTI-PEAK OPTICAL REFERENCE ELEMENT AND BIREFRINGENT SENSOR SYSTEM

Certain aspects of the present disclosure generally relate to an optical reference element having a wavelength spectrum comprising a plurality of wavelength functions having wavelength peaks spaced over a range of wavelengths, wherein adjacent wavelength functions are due to two orthogonal birefringence axes in the optical reference element. Aspects of the present disclosure may eliminate the drift issues associated with residual polarization and polarization dependent loss (PDL) with respect to grating-based sensor and reference element measurements. 1. An optical reference element having a wavelength spectrum comprising a plurality of wavelength functions having wavelength peaks spaced over a range of wavelengths , wherein adjacent wavelength functions are due to two orthogonal birefringence axes in the optical reference element.2. The optical reference element of claim 1 , wherein edges of the adjacent wavelength functions do not significantly overlap.3. The optical reference element of claim 1 , wherein the adjacent wavelength functions are distinguishable over a range of environmental operating conditions for the optical reference element.4. The optical reference element of claim 1 , further comprising:a core;a stress feature configured to generate the two orthogonal birefringence axes for light propagated in the core; anda cladding surrounding the core and the stress feature.5. The optical reference element of claim 4 , wherein an outer diameter of the cladding is at least 0.3 mm.6. The optical reference element of claim 4 , wherein the stress feature has an elliptical shape in cross-section.7. The optical reference element of claim 4 , wherein the stress feature comprises two holes in the cladding and wherein the two holes are parallel to the core.8. The optical reference element of claim 4 , wherein the stress feature comprises two glass rods disposed in the cladding and parallel to the core and wherein the two glass rods have a thermal expansion coefficient ...

SECURING METHOD, SECURING DEVICE, USE OF A SECURING DEVICE AND TEMPERATURE SENSOR

The invention relates to a securing method, comprising the following Steps: providing an optical waveguide made of a material with a first melting temperature, wherein a sensor region of the optical waveguide has at least one integrated temperature sensor element; providing a capillary made of a material with a second melting temperature, in such a way that the capillary surrounds at least regions of the sensor region of the optical waveguide, and that a securing region of the capillary is arranged at a distance from the sensor region, wherein the second melting temperature is lower than the first melting temperature, wherein the temperature sensor element is arranged in an end region of the optical waveguide, and the end region is inserted into the capillary; securing the securing region of the capillary to the optical waveguide, involving a heating of the securing region of the capillary to a heating temperature that is equal to or higher than the second melting temperature; and heating the free end of the capillary to a heating temperature that is equal to or higher than the second melting temperature. A temperature sensor comprising an optical waveguide with at least one integrated temperature sensor element can be obtained with the method. A securing device comprises an Insertion region for the capillary, a detector and a heating region. The securing device can be used for carrying out the method. 1. A securing method , comprising:providing an optical waveguide made of a material with a first melting temperature, wherein a sensor region of the optical waveguide comprises at least one integrated temperature sensor element;providing a capillary made of a material with a second melting temperature in such a way that the capillary surrounds at least regions of the sensor region of the optical waveguide, and that a securing region of the capillary is arranged at a distance from the sensor region, wherein the second melting temperature is lower than the first melting ...

Optical Fibre And Optical Fibre Device

An optical fibre () which has a first refractive index profile () that can be changed by heating to a second refractive index profile (), at least one first dopant () for providing the first refractive index profile, at least one concealed dopant (), and at least one mobile dopant (), wherein the mobile dopant has a molar refractivity and is present in a concentration () such as to balance a change () in the first refractive index profile induced by the concealed dopant, and has a diffusion constant () greater than a diffusion constant () of the concealed dopant, so that heating of the optical fibre causes the mobile dopant to diffuse more quickly than the concealed dopant, thereby allowing the concealed dopant and the mobile dopant to change the first refractive index profile to the second refractive index profile. 1. An optical fibre which has a first refractive index profile that can be changed by heating to a second refractive index profile , the optical fibre comprising at least one core , a cladding , at least one first dopant for providing the first refractive index profile , at least one concealed dopant , and at least one mobile dopant , the core having a refractive index that is greater than a refractive index of the cladding , and the optical fibre being characterized in that:one of the concealed dopant and the mobile dopant has a negative molar refractivity and the other one has a positive molar refractivity;the mobile dopant is present in a concentration to balance the change in the first refractive index profile induced by the concealed dopant;the concealed dopant is present in a concentration that if not balanced by the mobile dopant would change the first refractive index profile;the mobile dopant has a diffusion constant greater than a diffusion constant of the concealed dopant so that heating of the optical fibre causes the mobile dopant to diffuse more quickly than the concealed dopant, thereby allowing the concealed dopant and the mobile dopant ...

Raman fiber laser

Improved Raman Fiber Laser (RFL) generators may include a mid-infrared fiber, e.g., a fiber comprising a tellurite glass, a chalcogenide glass, a fluoride glass, or similar material. A phase-shifted fiber Bragg grating may be inscribed in the fiber. A pump laser generator may be coupled with the fiber in order to supply a pump laser to the fiber. When stimulated by the pump laser, the RFL generator may emit an output laser having a mid-infrared wavelength. A tuner may be used to tune the output laser.

METHOD TO OPTIMIZE A LIGHT COUPLING WAVEGUIDE

The present invention concerns a method for constructing a light coupling system wherein a grating is manufactured on the surface of a multimode waveguide and defines the entrance of the waveguide for an incident light beam, said grating comprising a repetition of patterns. The grating is defined by a set of parameters comprising: •grating period (P), separating two adjacent patterns, •grating depth (d) between the highest and the lowest point of the pattern, •incident angle mean value (θ) of the incident light with respect to the waveguide. The method comprises a step of optimization of the set of parameters to obtain an optimized second set of parameters, in order to obtain a transmission efficiency (Ce) of the incident light into said waveguide for the first or the second diffractive order exceeding 35% for unpolarized light, or exceeding 50% for polarized light, at a given wavelength of the incident light. 116-. (canceled)18. The method of claim 17 , wherein the shape of the pattern is rectangular claim 17 , and wherein said optimization step comprises the optimization of the rectangular fill factor (A/P) defined as the width of a rectangle (A) compared to the grating period (P).192. The method of claim 17 , wherein said grating is covered by an enhancement layer whose refractive index (n) belongs to the first set of parameters claim 17 , and whose thickness (L) belongs to the second set of parameters claim 17 , and whereinthe optimization step comprises the optimization of said layer thickness (L), and{'b': 2', '1, 'n-n is greater or equal to 0.3, preferably greater or equal to 0.5 preferably greater or equal to 0.8, and'}{'b': 2', '3, 'n-n is greater or equal to 0.3, preferably greater or equal to 0.5 preferably greater or equal to 0.8.'}202. The method of claim 18 , wherein said grating is covered by an enhancement layer whose refractive index (n) belongs to the first set of parameters claim 18 , and whose thickness (L) belongs to the second set of parameters ...

AVOIDING BEAM OBSTRUCTION DURING INSCRIPTION OF FIBER GRATINGS

The present disclosure provides systems and methods for avoiding beam obstructions during inscription of fiber gratings. For some embodiments, an optical fiber is re-oriented during fiber inscription to avoid obstruction of the actinic beam. 1. A twisted multicore optical fiber , comprising:cores, comprising a helical outer core, the helical outer core having a twist period; andgratings inscribed along a length of at least one of the cores, the gratings being inscribed using at least two exposures, each of the at least two exposures having a beam length that is longer than the twist period, the gratings comprising segments, each of the segments being exposed at least once without obstruction.2. The optical fiber of claim 1 , the cores further comprising a center core.3. The optical fiber of claim 1 , the twist rate being regular.4. The optical fiber of claim 1 , the twist rate being irregular.5. A method claim 1 , comprising:exposing a first location of a core of an optical fiber to actinic radiation, the actinic radiation to inscribe the first location with a grating, the inscribed grating having a finite length;axially moving the optical fiber an incremental distance, the incremental distance being less than the finite length;changing an orientation of the optical fiber with reference to a source of the actinic radiation by a predefined angle of rotation; andexposing a second location of the core with the actinic radiation.6. The method of claim 5 , the step of changing the orientation comprising the step of rotating the optical fiber.7. The method of claim 5 , the step of changing the orientation comprising the step of moving the actinic radiation source.8. The method of claim 5 , the step of changing the orientation comprising the step of twisting the optical fiber.9. The method of claim 5 , further comprising holding the optical fiber on a reel-to-reel system.10. The method of claim 5 , further comprising holding the optical fiber with clamps.11. A method claim ...

METHOD OF MAKING A DISTRIBUTED OPTICAL FIBER SENSOR HAVING ENHANCED RAYLEIGH SCATTERING AND ENHANCED TEMPERATURE STABILITY, AND MONITORING SYSTEMS EMPLOYING SAME

A method of making an optical fiber sensor device for distributed sensing includes generating a laser beam comprising a plurality of ultrafast pulses, and focusing the laser beam into a core of an optical fiber to form a nanograting structure within the core, wherein the nanograting structure includes a plurality of spaced nanograting elements each extending substantially parallel to a longitudinal axis of optical fiber. Also, an optical fiber sensor device for distributed sensing includes an optical fiber having a longitudinal axis, a core, and a nanograting structure within the core, wherein the nanograting structure includes a plurality of spaced nanograting elements each extending substantially parallel to the longitudinal axis of the optical fiber. Also, a distributed sensing method and system and an energy production system that employs such an optical fiber sensor device. 1. A method of making an optical fiber sensor device structured for distributed sensing , comprising:generating a laser beam comprising a plurality of ultrafast pulses; andfocusing the laser beam into a core of an optical fiber to form a nanograting structure within the core, wherein the nanograting structure includes a plurality of spaced nanograting elements each extending substantially parallel to a longitudinal axis of optical fiber.2. The method according to claim 1 , wherein the plurality of ultrafast pulses comprises a plurality of femtosecond ultrafast pulses.3. The method according to claim 2 , wherein each of the femtosecond ultrafast pulses is a sub-μJ laser pulse.4. The method according to claim 1 , further comprising causing the laser beam and the optical fiber to be moved relative to one another during focusing such that the nanograting structure is formed within a longitudinally extending portion of the core.5. The method according to claim 4 , wherein a position of the laser beam in a longitudinal direction is stationary and wherein the optical fiber is caused to move ...

OPTICAL FIBER HEAT DISSIPATION PACKAGE

A heat-dissipation package for use with an optical fiber includes a base, a cover, and a hollow sleeve. The base includes an upper surface, a lower surface, and a groove embedded in the upper surface, the groove having a generally U-shaped cross-sectional shape. The cover is positioned on the upper surface of the base. The sleeve includes a cylindrical inner surface and an outer surface with a first portion which has a generally U-shaped cross section and a second portion which has a generally planar cross section such that edges of the planar cross section contact an open end of the U-shaped cross section. The first portion of the outer surface of the sleeve is positioned in the groove and the second portion of the outer surface of the sleeve is in contact with the cover. The sleeve is configured to encapsulate a heat-generating section of the optical fiber. 1. A heat-dissipation package for use with an optical fiber with a heat-generating section , the optical fiber including a core which is surrounded by at least one cladding which is surrounded by at least one coating layer , the heat-generating section including the core and the at least one cladding and occupying a portion of an axial length of the optical fiber , the heat-dissipation package comprising:a base including an upper surface, a lower surface, two opposing end surfaces, and a groove embedded in the upper surface, the groove having a generally U-shaped cross-sectional shape;a cover including an upper surface, a lower surface, and two opposing end surfaces, the cover positioned on the upper surface of the base; anda hollow sleeve including a cylindrical inner surface and an outer surface with a first portion which has a generally U-shaped cross section and a second portion which has a generally planar cross section such that edges of the planar cross section contact an open end of the U-shaped cross section, the first portion of the outer surface of the sleeve positioned in the groove and the second ...

PHOTONIC APPARATUS FOR CONTROLLING POLARIZATION

A photonic device has a polarization-dependent region and a device layer including a first cladding film, a second cladding film, and a core film. The core film includes one of (1) a material having an index nand (2) alternating layers of a first material having a first index and second material having a second index. The alternating layers have an effective index for TE polarized light nand an effective index for TM polarized light n. Each of the first cladding film and the second cladding film include the other of (1) the material having the index of refraction nand (2) the alternating layers n Подробнее

Fiber-based saturable absorber

Methods, apparatus, and systems for active saturable absorbance of an optical beam. An active saturable absorber may comprise an optical input to receive an optical beam, and one or more lengths of fiber between the optical input and an optical output. At least one of the lengths of fiber comprises a confinement region that is optically coupled to the output. The active saturable absorber may further comprise an optical detector to sense a characteristic of the optical beam, such as power. The active saturable absorber may further comprise a perturbation device to modulate, through action upon the one or more lengths of fiber, a transmittance of the beam through a fiber confinement region from a lower transmittance level to a higher transmittance level based on an indication of the characteristic sensed while the transmittance level is low.

Multi-wavelength fiber laser

An optical beam delivery device, such as an optical fiber, includes: a first length of fiber having a first refractive index profile (RIP) to enable modification of one or more beam characteristics of an optical beam having a first wavelength; and a second length of fiber having at least one wavelength-modifying confinement region and situated to receive the optical beam from the first length of fiber.

Compensation Of Fiber Lensing Effect During Grating Fabrication In Multicore Fiber

An arrangement and method that compensates for variation in grating strength associated with forming multiple gratings in multicore fiber is proposed where the writing efficiency of the beam(s) used to form the gratings is controlled to compensate for fiber lensing effects. In one case, a spacing between the multicore optical fiber and the beam source is controlled such that the writing efficiency (which decreases as a function of the space between the source and the fiber) compensates (at least in part) for the increased beam intensity attributed to the lensing effect of the fiber itself. The width of beam itself may also be controlled to modify the writing efficiency. 1. A method for controlling grating strength created in multiple core regions of a multicore optical fiber , comprising the steps ofproviding a beam source for creating interfering and overlapping writing beams forming an interference pattern, an overlapped region defined as an interferogram region, with a number of interference fringes created by the overlapping beams defining a writing efficiency of the beam source;positioning a multicore optical fiber in proximity to the beam source such that the overlapping writing beams pass through a width of the multicore optical fiber; andadjusting the interferogram region to control the writing efficiency of the interferogram and thereby control the strength of gratings created in different core regions of the multicore optical fiber.2. The method as defined in wherein the method further comprises the step of:translating the position of the beam source along a length of the multicore optical fiber to create multiple gratings of predetermined lengths.3. The method as defined in wherein the method further includes the step of modulating the interferogram region as the beam source is translated along the multicore optical fiber.4. The method as defined in wherein the interferogram region is phase modulated.5. The method as defined in wherein the interferogram ...

OPTICAL FIBER WITH INTEGRATED ABSORBER MATERIAL

In a multicore optical fiber sensor, an absorptive material integrated into the cladding, or into a waveguide core not used for sensing, may facilitate sensing. The absorptive material is absorptive to light in a wavelength band in which the fiber sensor is configured to operate. Coating such a fiber sensor with a material whose refractive index is smaller than that of the cladding may be done with reduced signal mixing. 1. An optical fiber sensor configured to operate in a wavelength band , the fiber sensor comprising:a cladding;a plurality of cores in the cladding and extending along a length of the fiber sensor, the plurality of cores including at least one sensing core; anda coating surrounding the cladding, the coating having a refractive index smaller than a refractive index of the cladding,wherein at least one of the cladding and a helical core of the plurality of cores comprises an absorber material absorptive to light in the wavelength band.2. The fiber sensor of claim 1 , wherein the plurality of cores comprises a plurality of sensing cores.3. The fiber sensor of claim 1 , wherein the helical core comprises the absorber material claim 1 , and wherein the helical core is not used for sensing in the wavelength band.4. The fiber sensor of claim 1 , wherein the coating is substantially made of a polymer.5. The fiber sensor of claim 1 , wherein the coating is at least partially transparent to ultraviolet light.6. The fiber sensor of claim 1 , wherein the cladding comprises fused silica.7. The fiber sensor of claim 1 , wherein the absorber material comprises one or more of: erbium claim 1 , ytterbium claim 1 , thulium claim 1 , neodymium claim 1 , chromium claim 1 , and cobalt.8. (canceled)9. The fiber sensor of claim 1 , wherein the cladding and the plurality of cores is formed from a preform of stacked rods claim 1 , and wherein the at least one sensing core is formed from at least one stacked rod comprising a doped core claim 1 , and wherein the helical core ...

PHOTONIC APPARATUS FOR CONTROLLING POLARIZATION

A photonic device has a polarization-dependent region and a device layer including a first cladding film, a second cladding film, and a core film. The core film includes one of (1) a material having an index nand (2) alternating layers of a first material having a first index and second material having a second index. The alternating layers have an effective index for TE polarized light nand an effective index for TM polarized light n. Each of the first cladding film and the second cladding film include the other of (1) the material having the index of refraction nand (2) the alternating layers n Подробнее

DIRECTIONAL SENSITIVE FIBER OPTIC CABLE WELLBORE SYSTEM

A fiber optic cable assembly includes an elongate housing, a signal fiber placed inside the housing and extending longitudinally, and a plurality of sensing fibers placed inside the housing and extending longitudinally. The plurality of sensing fibers is placed around the signal fiber. Each of the plurality of sensing fibers carries a respective laser signal of a distinct frequency. The signal fiber carries one or more evanescent coupling signals responsive to the laser signals in the plurality of sensing fibers. 1. A fiber optic cable assembly , comprising:an elongate housing;a signal fiber placed inside the housing and extending longitudinally;a strap to secure the fiber optic cable assembly outside a tubing in a wellbore formed in a formation; anda plurality of sensing fibers placed inside the housing and extending longitudinally, wherein the plurality of sensing fibers are placed around the signal fiber, each of the plurality of sensing fibers carries a respective laser signal of a distinct frequency, and the signal fiber carries one or more evanescent coupling signals responsive to the laser signals in the plurality of sensing fibers.2. The fiber optic cable assembly of claim 1 , wherein the plurality of sensing fibers placed around the signal fiber includes the plurality of sensing fibers arranged in a circle with the signal fiber placed in the middle of the housing.3. The fiber optical cable assembly of claim 1 , further comprising a high density fluid to keep the signal fiber and the plurality of sensing fibers in the housing immobilized.4. The fiber optic cable assembly of claim 1 , further comprising:a plurality of mirrors dividing a space inside the housing into a plurality of isolated sections, each isolated section extending longitudinally, each isolated section including one of the plurality of sensing fibers.5. The fiber optic cable assembly of claim 1 , wherein the housing has a circular cross-section.6. The fiber optic cable assembly of claim 1 , ...