Spatially Multiplexed Dielectric Metasurface Optical Elements

A multifunctional dielectric gradient metasurface optical device has a layer of nanoscale dielectric gradient metasurface optical antenna elements deposited on a substrate layer, arranged with spatially varying orientations, shapes, or sizes in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping. The spatially varying optical phase response is a spatial interleaving of multiple distinct phase profiles corresponding to multiple optical sub-elements, thereby providing multifunctional wavefront shaping in the single optical element. 1. A metasurface optical device comprising a layer of nanoscale metasurface optical antenna elements deposited on a substrate layer , wherein the optical antenna elements are arranged with spatially varying characteristics in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping , wherein the spatially varying optical phase response is a spatial interleaving of multiple distinct phase profiles , thereby providing multifunctional wavefront shaping.2. The metasurface optical device of wherein the layer of nanoscale metasurface optical antenna elements is a dielectric gradient metasurface optical element.3. The metasurface optical device of wherein the layer of nanoscale metasurface optical antenna elements is composed of dielectric materials claim 1 , high-index semiconductor material claim 1 , or insulator-and-metal materials.4. The metasurface optical device of wherein the optical antenna elements are arranged in the plane of the device with spatially varying orientation claim 1 , shape claim 1 , or size.5. The metasurface optical device of wherein the optical antenna elements are implemented by nanobeams claim 1 , nanofins claim 1 , ellipse nanoparticles claim 1 , or circular nanoparticles.6. The metasurface optical device of wherein the layer of nanoscale metasurface ...

Metasurfaces with asymmetric gratings for redirecting light and methods for fabricating

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 μm. The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 μm where the refractive index is 3.3 or less.

METASURFACES WITH ASYMMETRIC GRATINGS FOR REDIRECTING LIGHT AND METHODS FOR FABRICATING

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 μm. The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 μm where the refractive index is 3.3 or less. 1. An optical system comprising: a laterally-elongated first nanobeam having a first width; and', 'a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width,', 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and', '10 nm to 1 μm where the refractive index is 3.3 or less., 'wherein heights of the first and the second nanobeams are], 'a grating comprising a plurality of unit cells, each unit cell comprising, 'an optically transmissive substrate comprising a metasurface, the metasurface comprising, as seen in a top-down view2. The optical system of claim 1 , wherein the unit cells are laterally-elongated and are parallel to each other.3. The optical system of claim 1 , wherein the metasurface is configured to diffract incident light of a visible wavelength into a first diffraction order.4. The optical system of claim 1 , wherein the second width is 10 nm to 1 μm.5. The optical system of claim 4 , wherein the second width is 10 nm to 300 nm.6. The optical system of claim 1 , wherein a pitch of the unit cells is 10 nm to 1 μm.7. The optical system of claim 6 , wherein the pitch of the unit cells is 10 nm to 500 nm.8. The optical system of claim 1 , wherein the first nanobeam and the second nanobeam are separated by a gap of 10 ...

ANTIREFLECTION COATINGS FOR METASURFACES

Antireflection coatings for metasurfaces are described herein. In some embodiments, the metasurface may include a substrate, a plurality of nanostructures thereon, and an antireflection coating disposed over the nanostructures. The antireflection coating may be a transparent polymer, for example a photoresist layer, and may have a refractive index lower than the refractive index of the nanostructures and higher than the refractive index of the overlying medium (e.g., air). Advantageously, the antireflection coatings may reduce or eliminate ghost images in an augmented reality display in which the metasurface is incorporated. 1. An optical system comprising:an optically transmissive substrate;a metasurface overlying the substrate, the metasurface comprising a plurality of nanostructures; andan antireflection coating comprising an optically transparent material conformally disposed over the nanostructures of the metasurface, wherein the optically transparent material has a refractive index less than a refractive index of the nano structures.2. The optical system of claim 1 , wherein the antireflection coating is an interference coating.3. The optical system of claim 1 , wherein the metasurface comprises a diffraction grating.4. The optical system of claim 3 , wherein the metasurface comprises an asymmetric diffraction grating.5. The optical system of any one of claims 1 , wherein the metasurface comprises a Pancharatnam-Berry phase optical element (PBOE).6. The optical system of claim 1 , wherein the metasurface comprises multi-tier nano structures.7. The optical system of claim 1 , wherein the optically transparent material comprises a polymer.8. The optical system of claim 7 , wherein the optically transparent material comprises photoresist.9. The optical system of claims 1 , wherein the optically transparent material has a refractive index from about 1.2 to about 2.10. The optical system of claim 1 , wherein a distance from a topmost surface of the nanostructures ...

Metasurfaces with asymetric gratings for redirecting light and methods for fabricating

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 μm. The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 μm where the refractive index is 3.3 or less.

DIFFRACTION GRATINGS FORMED BY METASURFACES HAVING DIFFERENTLY ORIENTED NANOBEAMS

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization.

Diffraction gratings formed by metasurfaces having differently oriented nanobeams

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization.

METASURFACES FOR REDIRECTING LIGHT AND METHODS FOR FABRICATING

A display system comprises a waveguide having light incoupling or light outcoupling optical elements formed of a metasurface. The metasurface is a multilevel (e.g., bi-level) structure having a first level defined by spaced apart protrusions formed of a first optically transmissive material and a second optically transmissive material between the protrusions. The metasurface also includes a second level formed by the second optically transmissive material. The protrusions on the first level may be patterned by nanoimprinting the first optically transmissive material, and the second optically transmissive material may be deposited over and between the patterned protrusions. The widths of the protrusions and the spacing between the protrusions may be selected to diffract light, and a pitch of the protrusions may be 10-600 nm.

METASURFACES WITH ASYMETRIC GRATINGS FOR REDIRECTING LIGHT AND METHODS FOR FABRICATING

An optical system comprises an optically transmissive substrate comprising a multilevel metasurface which comprises a grating comprising a plurality of multilevel unit cells. Each unit cell comprises, on a lowermost level, a laterally-elongated first lowermost level nanobeam having a first width and a laterally-elongated second lowermost level nanobeam having a second width larger than the first width. Each unit cell further comprises, on an uppermost level, a laterally-elongated first uppermost level nanobeam above the first lowermost level nanobeam and a laterally-elongated second uppermost level nanobeam above the second lowermost level nanobeam.

Metasurfaces for redirecting light and methods for fabricating

A display system comprises a waveguide having light incoupling or light outcoupling optical elements formed of a metasurface. The metasurface is a multilevel (e.g., bi-level) structure having a first level defined by spaced apart protrusions formed of a first optically transmissive material and a second optically transmissive material between the protrusions. The metasurface also includes a second level formed by the second optically transmissive material. The protrusions on the first level may be patterned by nanoimprinting the first optically transmissive material, and the second optically transmissive material may be deposited over and between the patterned protrusions. The widths of the protrusions and the spacing between the protrusions may be selected to diffract light, and a pitch of the protrusions may be 10-600 nm.

DIFFRACTION GRATINGS FORMED BY METASURFACES HAVING DIFFERENTLY ORIENTED NANOBEAMS

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization. 160-. (canceled)61. A method of fabricating an optical system , comprising:providing a substrate; forming the first set of nanobeams comprising one or more first nanobeams; and', 'forming the second set of nanobeams adjacent to the one or more first nanobeams, the second set of nanobeams comprising a plurality of second nanobeams that are separated from each other by a sub-wavelength spacing, wherein the wavelength is a visible light wavelength,', 'wherein the one or more first nanobeams and the plurality of second nanobeams are elongated in different orientation directions, and', 'wherein the unit cells repeat at a period less than or equal to the wavelength., 'forming a metasurface on the substrate, the metasurface comprising a plurality of unit cells, each of the unit cells comprising first and second sets of nanobeams, wherein forming the unit cells comprises62. The method of claim 61 , wherein forming the one or more first nanobeams and forming the second nanobeams comprises lithographically defining the first and second nanobeams.63. The method of claim 61 , wherein forming the one or more ...

PVH in-band chromatic correction using metasurface

An optical device includes an optical component (e.g., a polarization volume hologram, a geometric phase device, or a polarization-insensitive diffractive optical element) having a uniform thickness and configured to modify a wavefront of a light beam that includes light in two or more wavelengths visible to human eyes, where the optical component has a chromatic aberration between the two or more wavelengths. The optical device also includes a metasurface on the optical component. The metasurface includes a plurality of nanostructures configured to modify respective phases of incident light at a plurality of regions of the metasurface, where the plurality of nanostructures is configured to, at each region of the plurality of regions, add a respective phase delay for each of the two or more wavelengths to correct the chromatic aberration between the two or more wavelengths.

METASURFACES WITH ASYMETRIC GRATINGS FOR REDIRECTING LIGHT AND METHODS FOR FABRICATING

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 μm. The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 μm where the refractive index is 3.3 or less. 120-. (canceled)21. A method for forming a metasurface , the method comprising:providing an optically transmissive substrate; a laterally-elongated first nanobeam having a first width; and', 'a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width,, 'forming a grating comprising a plurality of unit cells across a major surface of the substrate, each unit cell comprising, as seen in a top-down viewdepositing a layer of optically transmissive spacer material in the gap and between the unit cells; anddepositing a reflective layer on the layer of spacer material, wherein the spacer material separates the grating from the reflective layer.22. The method of claim 21 , wherein the spacer material has a refractive index of 1 to 2.23. The method of claim 21 , wherein the reflective layer comprises aluminum.24. The method of claim 21 , wherein forming the grating comprises:depositing an optically transmissive layer over the substrate; andpatterning the optically transmissive layer to define the grating.25. The method of claim 24 , wherein patterning the optically transmissive layer comprises:providing a resist layer over the optically transmissive layer;defining a pattern in the resist layer; andtransferring the pattern from the resist layer to the optically ...

FLAT SPECTRAL RESPONSE GRATINGS USING HIGH INDEX MATERIALS

An example head-mounted display device includes a plurality of optical elements in optical communication. The optical elements are configured to project an image in a field of view of a user wearing the head-mounted display device. A first optical element is configured to receive light from a second optical element. The first optical element defines a grating at along a periphery of the first optical element. The grating includes a plurality of protrusions extending from a base portion of the first optical element. The protrusions include a first material having a first optical dispersion profile for visible wavelengths of light. The grating also includes a second material disposed between at least some of the plurality of protrusions along the base portion of the first optical element. The second material has a second optical dispersion profile for visible wavelengths of light.

MULTI-LAYER DIFFRACTIVE EYEPIECE

An eyepiece for projecting an image to an eye of a viewer includes a waveguide configured to propagate light in a first wavelength range, and a grating coupled to a back surface of the waveguide. The grating is configured to diffract a first portion of the light propagating in the waveguide out of a plane of the waveguide toward a first direction, and to diffract a second portion of the light propagating in the waveguide out of the plane of the waveguide toward a second direction opposite to the first direction. The eyepiece furthers include a wavelength-selective reflector coupled to a front surface of the waveguide. The wavelength selective reflector is configured to reflect light in the first wavelength range and transmit light outside the first wavelength range, such that the wavelength-selective reflector reflects at least part of the second portion of the light back toward the first direction. 1. An eyepiece for projecting an image to an eye of a viewer , the eyepiece comprising:a planar waveguide having a front surface and a back surface, the planar waveguide being configured to propagate light in a first wavelength range;a grating coupled to the back surface of the planar waveguide and configured to diffract a first portion of the light propagating in the planar waveguide out of a plane of the planar waveguide toward a first direction and to diffract a second portion of the light propagating in the planar waveguide out of the plane of the planar waveguide toward a second direction opposite to the first direction; anda wavelength-selective reflector coupled to the front surface of the planar waveguide and configured to reflect light in the first wavelength range and transmit light outside the first wavelength range, such that the wavelength-selective reflector reflects at least part of the second portion of the light back toward the first direction.2. The eyepiece of wherein the first direction is toward the eye of the viewer claim 1 , and the second ...

METASURFACES WITH LIGHT-REDIRECTING STRUCTURES INCLUDING MULTIPLE MATERIALS AND METHODS FOR FABRICATING

Display devices include waveguides with metasurfaces as in-coupling and/or out-coupling optical elements. The metasurfaces may be formed on a surface of the waveguide and may include a plurality or an array of sub-wavelength-scale (e.g., nanometer-scale) protrusions. Individual protrusions may include horizontal and/or vertical layers of different materials which may have different refractive indices, allowing for enhanced manipulation of light redirecting properties of the metasurface. Some configurations and combinations of materials may advantageously allow for broadband metasurfaces. Manufacturing methods described herein provide for vertical and/or horizontal layers of different materials in a desired configuration or profile. 1. An optical system comprising:a waveguide; a first vertical layer comprising a first material; and', 'a second vertical layer comprising a second material different from the first material., 'a plurality of spaced-apart protrusions disposed on the waveguide, each protrusion comprising, 'an optical element on a surface of the waveguide, the optical element configured to redirect light having a wavelength, the optical element comprising2. The optical system of claim 1 , wherein the optical element is a metasurface.3. The optical system of claim 1 , wherein the first material and the second material have different refractive indices.4. The optical system of claim 1 , wherein the first vertical layer defines a u-shaped cross-sectional profile claim 1 , wherein the second material fills an interior volume of the u-shape.5. The optical system of claim 1 , wherein each protrusion further comprises an intermediate vertical layer disposed between the first vertical layer and the second vertical layer claim 1 , the intermediate vertical layer comprising a third material different from the first material and the second material.6. The optical system of claim 5 , wherein the intermediate vertical layer and the second vertical layer both have u- ...

Metasurfaces with asymmetric gratings for redirecting light and methods for fabricating

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 μm. The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 μm where the refractive index is 3.3 or less.

MULTI-LAYER DIFFRACTIVE EYEPIECE

An eyepiece for projecting an image to an eye of a viewer includes a waveguide configured to propagate light in a first wavelength range, and a grating coupled to a back surface of the waveguide. The grating is configured to diffract a first portion of the light propagating in the waveguide out of a plane of the waveguide toward a first direction, and to diffract a second portion of the light propagating in the waveguide out of the plane of the waveguide toward a second direction opposite to the first direction. The eyepiece furthers include a wavelength-selective reflector coupled to a front surface of the waveguide. The wavelength selective reflector is configured to reflect light in the first wavelength range and transmit light outside the first wavelength range, such that the wavelength-selective reflector reflects at least part of the second portion of the light back toward the first direction. 1. An eyepiece for projecting an image to an eye of a viewer , the eyepiece comprising:a planar waveguide configured to propagate light in a first wavelength range;a grating coupled to the planar waveguide and configured to diffract a first portion of the light propagating in the planar waveguide out of a plane of the planar waveguide toward a first direction and to diffract a second portion of the light out of the plane of the planar waveguide toward a second direction opposite to the first direction;a front cover plate disposed substantially parallel to and in front of the planar waveguide; anda wavelength-selective reflector coupled to the front cover plate and configured to reflect light in the first wavelength range and transmit light outside the first wavelength range, such that the wavelength-selective reflector reflects at least part of the second portion of the light back toward the first direction.2. The eyepiece of wherein the grating is coupled to a front surface of the planar waveguide claim 1 , and wherein the front surface of the planar waveguide faces ...

EYEPIECES FOR USE IN WEARABLE DISPLAY SYSTEMS

An example a head-mounted display device includes a light projector and an eyepiece. The eyepiece is arranged to receive light from the light projector and direct the light to a user during use of the wearable display system. The eyepiece includes a waveguide having an edge positioned to receive light from the display light source module and couple the light into the waveguide. The waveguide includes a first surface and a second surface opposite the first surface. The waveguide includes several different regions, each having different grating structures configured to diffract light according to different sets of grating vectors.

INLINE IN-COUPLING OPTICAL ELEMENTS

A display system includes a waveguide assembly having a plurality of waveguides, each waveguide associated with an in-coupling optical element configured to in-couple light into the associated waveguide. A projector outputs light from one or more spatially-separated pupils, and at least one of the pupils outputs light of two different ranges of wavelengths. The in-coupling optical elements for two or more waveguides are inline, e.g. vertically aligned, with each other so that the in-coupling optical elements are in the path of light of the two different ranges of wavelengths. The in-coupling optical element of a first waveguide selectively in-couples light of one range of wavelengths into the waveguide, while the in-coupling optical element of a second waveguide selectively in-couples light of another range of wavelengths. Absorptive color filters are provided forward of an in-coupling optical element to limit the propagation of undesired wavelengths of light to that in-coupling optical element. 1. A display system comprising:{'claim-text': ['a first absorptive optical filter transmissive to light of a first range of wavelengths and absorptive to light of wavelengths different from the first range of wavelengths;', 'a first in-coupling optical element configured to receive light transmitted through the first absorptive optical filter; and', 'a first waveguide having a first major surface and a second major surface,', 'wherein the first in-coupling optical element is configured to incouple light of the first range of wavelengths into the first waveguide.'], '#text': 'a stack of waveguides comprising:'}2. The display system of claim 1 , wherein the first in-coupling optical element is on the first major surface of the first waveguide or the second major surface of the first waveguide.3. The display system of any of claim 1 , further comprising a second absorptive optical filter on one or both of the first or second major surfaces of the first waveguide claim 1 , ...

Multi-layer diffractive eyepiece with wavelength-selective reflector

An eyepiece for projecting an image to an eye of a viewer includes a waveguide configured to propagate light in a first wavelength range, and a grating coupled to a back surface of the waveguide. The grating is configured to diffract a first portion of the light propagating in the waveguide out of a plane of the waveguide toward a first direction, and to diffract a second portion of the light propagating in the waveguide out of the plane of the waveguide toward a second direction opposite to the first direction. The eyepiece furthers include a wavelength-selective reflector coupled to a front surface of the waveguide. The wavelength selective reflector is configured to reflect light in the first wavelength range and transmit light outside the first wavelength range, such that the wavelength-selective reflector reflects at least part of the second portion of the light back toward the first direction.

Spatially multiplexed dielectric metasurface optical elements

A multifunctional dielectric gradient metasurface optical device has a layer of nanoscale dielectric gradient metasurface optical antenna elements deposited on a substrate layer, arranged with spatially varying orientations, shapes, or sizes in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping. The spatially varying optical phase response is a spatial interleaving of multiple distinct phase profiles corresponding to multiple optical sub-elements, thereby providing multifunctional wavefront shaping in the single optical element.

Flat spectral response gratings using high index materials

An example head-mounted display device includes a plurality of optical elements in optical communication. The optical elements are configured to project an image in a field of view of a user wearing the head-mounted display device. A first optical element is configured to receive light from a second optical element. The first optical element defines a grating at along a periphery of the first optical element. The grating includes a plurality of protrusions extending from a base portion of the first optical element. The protrusions include a first material having a first optical dispersion profile for visible wavelengths of light. The grating also includes a second material disposed between at least some of the plurality of protrusions along the base portion of the first optical element. The second material has a second optical dispersion profile for visible wavelengths of light.

Eyepieces for use in wearable display systems

An example a head-mounted display device includes a light projector and an eyepiece. The eyepiece is arranged to receive light from the light projector and direct the light to a user during use of the wearable display system. The eyepiece includes a waveguide having an edge positioned to receive light from the display light source module and couple the light into the waveguide. The waveguide includes a first surface and a second surface opposite the first surface. The waveguide includes several different regions, each having different grating structures configured to diffract light according to different sets of grating vectors.

MULTI-LAYER DIFFRACTIVE EYEPIECE

An eyepiece includes a planar waveguide having a front surface and a back surface. The eyepiece also includes a grating coupled to the back surface of the planar waveguide and configured to diffract a first portion of the light propagating in the planar waveguide out of a plane of the planar waveguide toward a first direction and to diffract a second portion of the light propagating in the planar waveguide out of the plane of the planar waveguide toward a second direction opposite to the first direction and a wavelength-selective reflector coupled to the front surface of the planar waveguide. The wavelength-selective reflector comprises a multilevel metasurface comprising a plurality of spaced apart protrusions having a pitch and formed of a first optically transmissive material and a second optically transmissive material disposed between the spaced apart protrusions.

Light-field imaging using a gradient metasurface optical element

Embodiments of 3D imaging systems that use a multifunctional, nano structured metalens to replace the conventional microlens array in light field imaging are disclosed. The optical focusing properties of the metalenses provided by gradient metasurface optical elements. The gradient metasurfaces allow the properties of the elements of the metalens array to be changed by tuning the gradient metasurfaces.

Metasurfaces with light-redirecting structures including multiple materials and methods for fabricating

Display devices include waveguides with metasurfaces as in-coupling and/or out-coupling optical elements. The metasurfaces may be formed on a surface of the waveguide and may include a plurality or an array of sub-wavelength-scale (e.g., nanometer-scale) protrusions. Individual protrusions may include horizontal and/or vertical layers of different materials which may have different refractive indices, allowing for enhanced manipulation of light redirecting properties of the metasurface. Some configurations and combinations of materials may advantageously allow for broadband metasurfaces. Manufacturing methods described herein provide for vertical and/or horizontal layers of different materials in a desired configuration or profile.

DIFFRACTION GRATINGS FORMED BY METASURFACES HAVING DIFFERENTLY ORIENTED NANOBEAMS

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization. 1. An optical system comprising: a first set of nanobeams are formed by one or more first nanobeams; and', 'a second set of nanobeams are formed by a plurality of second nanobeams disposed adjacent to the one or more first nanobeams and separated from each other by a sub-wavelength spacing,', 'wherein the one or more first nanobeams and the plurality of second nanobeams are elongated in different orientation directions, and', 'wherein the unit cells repeat at a period less than or equal to about 10 nm to 1 μm., 'a plurality of repeating unit cells, each unit cell consisting of two to four sets of nanobeams, wherein, 'a metasurface configured to diffract visible light having a wavelength, the metasurface comprising2. The optical system of claim 1 , wherein the one or more first nanobeams and the second nanobeams are oriented at an angle relative to each other to cause a phase difference between the visible light diffracted by the one or more first nanobeams and the visible light diffracted by the second nanobeams.3. The optical system of claim 1 , wherein the phase difference is twice the angle.4. ...

ANTIREFLECTION COATINGS FOR METASURFACES

Antireflection coatings for metasurfaces are described herein. In some embodiments, the metasurface may include a substrate, a plurality of nanostructures thereon, and an antireflection coating disposed over the nanostructures. The antireflection coating may be a transparent polymer, for example a photoresist layer, and may have a refractive index lower than the refractive index of the nanostructures and higher than the refractive index of the overlying medium (e.g., air). Advantageously, the antireflection coatings may reduce or eliminate ghost images in an augmented reality display in which the metasurface is incorporated.

Metasurfaces for redirecting light and methods for fabricating

A display system comprises a waveguide having light incoupling or light outcoupling optical elements formed of a metasurface. The metasurface is a multilevel (e.g., bi-level) structure having a first level defined by spaced apart protrusions formed of a first optically transmissive material and a second optically transmissive material between the protrusions. The metasurface also includes a second level formed by the second optically transmissive material. The protrusions on the first level may be patterned by nanoimprinting the first optically transmissive material, and the second optically transmissive material may be deposited over and between the patterned protrusions. The widths of the protrusions and the spacing between the protrusions may be selected to diffract light, and a pitch of the protrusions may be 10-600 nm.

Antireflection coatings for metasurfaces

Antireflection coatings for metasurfaces are described herein. In some embodiments, the metasurface may include a substrate, a plurality of nanostructures thereon, and an antireflection coating disposed over the nanostructures. The antireflection coating may be a transparent polymer, for example a photoresist layer, and may have a refractive index lower than the refractive index of the nanostructures and higher than the refractive index of the overlying medium (e.g., air). Advantageously, the antireflection coatings may reduce or eliminate ghost images in an augmented reality display in which the metasurface is incorporated.

METASURFACES FOR REDIRECTING LIGHT AND METHODS FOR FABRICATING

A display system comprises a waveguide having light incoupling or light outcoupling optical elements formed of a metasurface. The metasurface is a multilevel (e.g., bi-level) structure having a first level defined by spaced apart protrusions formed of a first optically transmissive material and a second optically transmissive material between the protrusions. The metasurface also includes a second level formed by the second optically transmissive material. The protrusions on the first level may be patterned by nanoimprinting the first optically transmissive material, and the second optically transmissive material may be deposited over and between the patterned protrusions. The widths of the protrusions and the spacing between the protrusions may be selected to diffract light, and a pitch of the protrusions may be 10-600 nm. 120-. (Cancelled)21. A near-eye display system comprising:a waveguide for outputting image information; a plurality of spaced-apart protrusions having a pitch and formed of a first optically transmissive material; and', 'an optically transmissive resist between the spaced-apart protrusions., 'a multilevel metasurface comprising, 'an optical element disposed on a surface of the waveguide, the optical element configured to in-couple or out-couple light for providing the image information, the optical element comprising22. The near-eye display system of claim 21 , wherein the plurality of spaced-apart protrusions are formed of resist having a different refractive index than the optically transmissive resist between the spaced-apart protrusions.23. The near-eye display system of claim 22 , wherein the optically transmissive resist between the spaced-apart protrusions has a higher refractive index than material forming the plurality of spaced-apart protrusions.24. The near-eye display system of claim 23 , wherein the optically transmissive resist between the spaced-apart protrusions has a higher refractive index than material forming the waveguide.25. ...

DETECTING PHYSICAL ASPECTS OF AN EYE USING INWARD-FACING SENSORS IN AN ARTIFICIAL REALITY HEADSET

Methods, systems, and storage media for eye tracking in artificial reality (e.g., virtual reality, augmented reality, mixed reality, etc.) headsets are disclosed. Exemplary implementations may: generate a simulated environment for a user through an artificial reality headset; track an eye of the user through an eye sensor responsive to the artificial reality headset being worn by the user; detect a physical aspect of the eye through the eye sensor indicative of an eye malady; and adjust a display setting of the artificial reality headset based at least in part on the detected physical aspect of the eye.

Communication in an artificial reality device due to predicted acquaintance interception

Methods, systems, and storage media for initiating communication between artificial reality devices are disclosed. Exemplary implementations may: enable a discovery setting by a first user wearing a first artificial reality device; detect a presence of at least a second user wearing a second artificial reality device; determine a familiarity level of the first user with the second user; and in response to the familiarity level breaching a familiarity threshold, initiate a call with the second artificial reality device by the first artificial reality device, the call including an interaction in an artificial reality environment accessed via the first artificial reality device and the second artificial reality device.

FLAT SPECTRAL RESPONSE GRATINGS USING HIGH INDEX MATERIALS

An example head-mounted display device includes a plurality of optical elements in optical communication. The optical elements are configured to project an image in a field of view of a user wearing the head-mounted display device. A first optical element is configured to receive light from a second optical element. The first optical element defines a grating at along a periphery of the first optical element. The grating includes a plurality of protrusions extending from a base portion of the first optical element. The protrusions include a first material having a first optical dispersion profile for visible wavelengths of light. The grating also includes a second material disposed between at least some of the plurality of protrusions along the base portion of the first optical element. The second material has a second optical dispersion profile for visible wavelengths of light.

Diffraction gratings formed by metasurfaces having differently oriented nanobeams

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization.

Multi-layer diffractive eyepiece with front cover plate and wavelength-selective reflector

An eyepiece for projecting an image to an eye of a viewer includes a waveguide configured to propagate light in a first wavelength range, and a grating coupled to a back surface of the waveguide. The grating is configured to diffract a first portion of the light propagating in the waveguide out of a plane of the waveguide toward a first direction, and to diffract a second portion of the light propagating in the waveguide out of the plane of the waveguide toward a second direction opposite to the first direction. The eyepiece furthers include a wavelength-selective reflector coupled to a front surface of the waveguide. The wavelength selective reflector is configured to reflect light in the first wavelength range and transmit light outside the first wavelength range, such that the wavelength-selective reflector reflects at least part of the second portion of the light back toward the first direction.

EYEPIECES FOR USE IN WEARABLE DISPLAY SYSTEMS

An example a head-mounted display device includes a light projector and an eyepiece. The eyepiece is arranged to receive light from the light projector and direct the light to a user during use of the wearable display system. The eyepiece includes a waveguide having an edge positioned to receive light from the display light source module and couple the light into the waveguide. The waveguide includes a first surface and a second surface opposite the first surface. The waveguide includes several different regions, each having different grating structures configured to diffract light according to different sets of grating vectors.

METASURFACES WITH ASYMETRIC GRATINGS FOR REDIRECTING LIGHT AND METHODS FOR FABRICATING

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 μm. The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 μm where the refractive index is 3.3 or less. 1. An optical system comprising: [ a laterally-elongated first nanobeam having a first width; and', 'a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width; and, 'a grating comprising a plurality of unit cells, each unit cell comprising, as seen in a top-down view, 'a reflector, wherein the reflector and the substrate are on opposite sides of the grating., 'an optically transmissive substrate comprising a metasurface, the metasurface comprising2. The optical system of claim 1 , wherein the reflector is spaced apart from the grating.3. The optical system of claim 2 , wherein the grating is embedded in an optically transmissive material.4. The optical system of claim 1 , wherein the optically transmissive material spaces the reflector apart from the grating.5. The optical system of claim 1 , wherein the substrate comprises: a laterally-elongated third nanobeam; and', 'a laterally-elongated fourth nanobeam spaced apart from the third nanobeam by a gap, wherein the fourth nanobeam is wider than the third nanobeam., 'a second grating comprising a plurality of second unit cells, each second unit cell comprising, as seen in a top-down view, 'a second metasurface on a side of the substrate opposite the metasurface, the second metasurface comprising6. The ...

Light-field Imaging Using a Gradient Metasurface Optical Element

Embodiments of 3D imaging systems that use a multifunctional, nano structured metalens to replace the conventional microlens array in light field imaging are disclosed. The optical focusing properties of the metalenses provided by gradient metasurface optical elements. The gradient metasurfaces allow the properties of the elements of the metalens array to be changed by tuning the gradient metasurfaces. 1. A multiplexed metalens array for a light imaging system comprising:dielectric gradient metasurface optical elements; and a plurality of interleaved sub-elements wherein at least two of the plurality of interleaved elements have different optical functionalities;', 'a phase profile of the multiplexed metalens array is a spatial multiplexing of the plurality of sub-elements., 'wherein the multiplexed metalens array includes2. The multiplexed metalens array of wherein each of the plurality of sub-elements have a different optical axis.3. The multiplexed metalens array of wherein at least two of the plurality of sub-elements have a different aperture.4. The multiplexed metalens array of wherein at least two of the plurality of elements have a different focal length.5. The multiplexed metalens of wherein each of the plurality of sub-elements are encoded with a coded aperture.6. The multiplexed metalens of wherein the plurality of sub-elements manipulate different states of polarization.7. The multiplexed metalens of wherein the dielectric gradient metasurface optical elements are silicon nanobeam antennas with a phase profile based on geometric phase.8. The multiplexed metalens of wherein the plurality of sub-elements include N sub-elements and an intensity claim 1 , I claim 1 , of an image generated decreases as a function of N such as N:I˜1/N.9. A field light imaging system comprising:a multiplexed metalens array made of dielectric gradient metasurface optical elements and wherein the arrays includes a plurality of interleaved sub-elements wherein at least two of the ...

Dielectric metasurface optical elements

A dielectric gradient metasurface optical device provides optical wavefront shaping using an ultrathin (less than 100 nm thick) layer of nanoscale geometric Pancharatnam-Berry phase optical elements deposited on a substrate layer. The optical elements are nanobeams composed of high refractive index dielectric material. The nanobeams have uniform size and shape and are arranged with less than 200 nm separations and spatially varying orientations in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping. The high refractive index dielectric material may be materials compatible with semiconductor electronic fabrication, including silicon, polysilicon, germanium, gallium arsenide, titanium dioxide, or iron oxide.

Dielectric Metasurface Optical Elements

A dielectric gradient metasurface optical device provides optical wavefront shaping using an ultrathin (less than 100 nm thick) layer of nanoscale geometric Pancharatnam-Berry phase optical elements deposited on a substrate layer. The optical elements are nanobeams composed of high refractive index dielectric material. The nanobeams have uniform size and shape and are arranged with less than 200 nm separations and spatially varying orientations in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping. The high refractive index dielectric material may be materials compatible with semiconductor electronic fabrication, including silicon, polysilicon, germanium, gallium arsenide, titanium dioxide, or iron oxide. 1. A dielectric gradient metasurface optical device comprising a less than 100 nm thick layer of nanoscale geometric Pancharatnam-Berry phase optical elements deposited on a substrate layer , wherein the optical elements are nanobeams composed of high refractive index dielectric material , wherein the nanobeams have uniform size and shape and are arranged with less than 200 nm separations and spatially varying orientations in the plane of the device such that the optical device has a spatially varying optical phase response capable of optical wavefront shaping.2. The optical device of wherein the high refractive index dielectric material is silicon.3. The optical device of wherein the high refractive index dielectric material is polysilicon claim 2 , germanium claim 2 , gallium arsenide claim 2 , titanium dioxide claim 2 , or iron oxide.4. The optical device of wherein the substrate is quartz or glass claim 1 , or other low refractive index material.5. The optical device of wherein the spatially varying optical phase response of the optical device functions as an optical blazed grating claim 1 , lens claim 1 , or axicon. Traditional optical components such as glass lenses shape ...

METASURFACES FOR REDIRECTING LIGHT AND METHODS FOR FABRICATING

A display system comprises a waveguide having light incoupling or light outcoupling optical elements formed of a metasurface. The metasurface is a multilevel (e.g., bi-level) structure having a first level defined by spaced apart protrusions formed of a first optically transmissive material and a second optically transmissive material between the protrusions. The metasurface also includes a second level formed by the second optically transmissive material. The protrusions on the first level may be patterned by nanoimprinting the first optically transmissive material, and the second optically transmissive material may be deposited over and between the patterned protrusions. The widths of the protrusions and the spacing between the protrusions may be selected to diffract light, and a pitch of the protrusions may be 10-600 nm. 1. A method for forming an optical waveguide , the method comprising: providing an optically transmissive resist layer overlying an optically transmissive substrate;', 'patterning the resist with a pattern comprising protrusions and intervening gaps, wherein the protrusions have a pitch in a range of 10 nm to 600 nm; and', 'depositing an optically transmissive material on the protrusions and into the gaps between the protrusions., 'forming a metasurface, wherein forming the metasurface comprises2. The method of claim 1 , wherein the optically transmissive material is amorphous.3. The method of claim 1 , wherein depositing the optically transmissive material forms spaced apart plateaus of the optically transmissive material above the protrusions.4. The method of claim 1 , wherein the optically transmissive material has a higher refractive index than either the patterned resist or the substrate.5. The method of claim 4 , wherein the refractive index of the optically transmissive material is higher than 1.7.6. The method of claim 4 , wherein the optically transmissive material is a resist.7. The method of claim 1 , wherein the optically transmissive ...

WAVEGUIDE WITH POLARIZATION VOLUME HOLOGRAM GRATING

A waveguide is provided. The waveguide includes a substrate having two outer surfaces for propagating a beam of light in the substrate by reflecting the beam from the two outer surfaces. The waveguide includes at least one polarization volume hologram (PVH) grating to couple light in and/or out of the waveguide. The PVH grating may be a multi-layer PVH grating with graded birefringence.

METASURFACES WITH LIGHT-REDIRECTING STRUCTURES INCLUDING MULTIPLE MATERIALS AND METHODS FOR FABRICATING

Display devices include waveguides with metasurfaces as in-coupling and/or out-coupling optical elements. The metasurfaces may be formed on a surface of the waveguide and may include a plurality or an array of sub-wavelength-scale (e.g., nanometer-scale) protrusions. Individual protrusions may include horizontal and/or vertical layers of different materials which may have different refractive indices, allowing for enhanced manipulation of light redirecting properties of the metasurface. Some configurations and combinations of materials may advantageously allow for broadband metasurfaces. Manufacturing methods described herein provide for vertical and/or horizontal layers of different materials in a desired configuration or profile.

Eyepieces for augmented reality display system

An eyepiece waveguide for an augmented reality display system. The eyepiece waveguide can include an optically transmissive substrate with an input coupling grating (ICG) region. The ICG region can receive a beam of light and couple the beam into the substrate in a guided propagation mode. The eyepiece waveguide can also include a combined pupil expander-extractor (CPE) grating region that receives the beam of light from the ICG region and alters the propagation direction of the beam with a first interaction and out-couples the beam with a second interaction. The diffractive features of the CPE grating region can be arranged in rows and columns of alternating higher and lower quadrilateral surfaces or the diffractive features can comprise diamond shaped raised ridges. The eyepiece waveguide can also include one or more recycler grating regions.

PVH IN-BAND CHROMATIC CORRECTION USING METASURFACE

An optical device includes an optical component (e.g., a polarization volume hologram, a geometric phase device, or a polarization-insensitive diffractive optical element) having a uniform thickness and configured to modify a wavefront of a light beam that includes light in two or more wavelengths visible to human eyes, where the optical component has a chromatic aberration between the two or more wavelengths. The optical device also includes a metasurface on the optical component. The metasurface includes a plurality of nanostructures configured to modify respective phases of incident light at a plurality of regions of the metasurface, where the plurality of nanostructures is configured to, at each region of the plurality of regions, add a respective phase delay for each of the two or more wavelengths to correct the chromatic aberration between the two or more wavelengths.

Antireflection coatings for metasurfaces

Antireflection coatings for metasurfaces are described herein. In some embodiments, the metasurtace may include a substrate, a plurality of nanostructures thereon, and an antireflection coating disposed over the nanostructures. The antireflection coating may be a transparent polymer, for example a photoresist layer, and may have a refractive index lower than the refractive index of the nanostructures and higher than the refractive index of the overlying medium (e.g., air). Advantageously, the antireflection coatings may reduce or eliminate ghost images in an augmented reality display in which the metasurtace is incorporated.

Diffraction gratings formed by metasurfaces having differently oriented nanobeams

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization.

Multi-layer diffractive eyepiece

Diffraction gratings formed by metasurfaces having differently oriented nanobeams

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization.

Metasurfaces with asymmetric gratings for redirecting light and methods for fabricating

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 µm The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 µm where the refractive index is 3.3 or less.

Eyepieces for augmented reality display system

An eyepiece waveguide for an augmented reality display system. The eyepiece waveguide can include an optically transmissive substrate with an input coupling grating (ICG) region. The ICG region can receive a beam of light and couple the beam into the substrate in a guided propagation mode. The eyepiece waveguide can also include a combined pupil expander-extractor (CPE) grating region that receives the beam of light from the ICG region and alters the propagation direction of the beam with a first interaction and out-couples the beam with a second interaction. The diffractive features of the CPE grating region can be arranged in rows and columns of alternating higher and lower quadrilateral surfaces or the diffractive features can comprise diamond shaped raised ridges. The eyepiece waveguide can also include one or more recycler grating regions.

Diffraction gratings formed by metasurfaces having differently oriented nanobeams

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 µm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization.

Metasurfaces with asymemtric gratings for redirecting light and methods for fabricating

An optical system comprises an optically transmissive substrate comprising a metasurface which comprises a grating comprising a plurality of unit cells. Each unit cell comprises a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width. A pitch of the unit cells is 10 nm to 1 μm The heights of the first and the second nanobeams are: 10 nm to 450 nm where a refractive index of the substrate is more than 3.3; and 10 nm to 1 μm where the refractive index is 3.3 or less.

Antireflection coatings for metasurfaces

Antireflection coatings for metasurfaces are described herein. In some embodiments, the metasurtace may include a substrate, a plurality of nanostructures thereon, and an antireflection coating disposed over the nanostructures. The antireflection coating may be a transparent polymer, for example a photoresist layer, and may have a refractive index lower than the refractive index of the nanostructures and higher than the refractive index of the overlying medium (e.g., air). Advantageously, the antireflection coatings may reduce or eliminate ghost images in an augmented reality display in which the metasurtace is incorporated.

Diffraction gratings formed by metasurfaces having differently oriented nanobeams

Metasurfaces provide compact optical elements in head-mounted display systems to, e.g., incouple light into or outcouple light out of a waveguide. The metasurfaces may be formed by a plurality of repeating unit cells, each unit cell comprising two sets or more of nanobeams elongated in crossing directions: one or more first nanobeams elongated in a first direction and a plurality of second nanobeams elongated in a second direction. As seen in a top-down view, the first direction may be along a y-axis, and the second direction may be along an x-axis. The unit cells may have a periodicity in the range of 10 nm to 1 μm, including 10 nm to 500 nm or 300 nm to 500 nm. Advantageously, the metasurfaces provide diffraction of light with high diffraction angles and high diffraction efficiencies over a broad range of incident angles and for incident light with circular polarization.

光を再指向させるための非対称格子を有するメタ表面および製造方法

【課題】光を再指向させるための非対称格子を有するメタ表面および製造方法の提供。【解決手段】光学システムは、複数のユニットセルを含む格子を含むメタ表面を含む、光学的に透過性の基板を含む。各ユニットセルは、第１の幅を有する、側方に伸長の第１のナノビームと、間隙によって前記第１のナノビームから離間される、側方に伸長の第２のナノビームとを含み、前記第２のナノビームは、前記第１の幅より大きい第２の幅を有する。前記ユニットセルのピッチは、１０ｎｍ～１μｍである。前記第１および第２のナノビームの高さは、１０ｎｍ～４５０ｎｍであって、前記基板の屈折率は、３．３を上回り、１０ｎｍ～１μｍであって、前記屈折率は、３．３またはそれ未満である。【選択図】図１０

Metasurfaces with asymmetric gratings for redirecting light and methods for fabricating

An optical system comprising: an optically transmissive substrate comprising a metasurface, the metasurface comprising: a grating comprising a plurality of unit cells, each unit cell comprising, as seen in a top-down view: a laterally-elongated first nanobeam having a first width; and a laterally-elongated second nanobeam spaced apart from the first nanobeam by a gap, the second nanobeam having a second width larger than the first width; and a reflector, wherein the reflector and the substrate are on opposite sides of the grating.

メタ表面のための反射防止コーティング

【課題】好適なメタ表面のための反射防止コーティングを提供すること。【解決手段】メタ表面のための反射防止コーティングが、本明細書に説明される。いくつかの実施形態では、メタ表面は、基板と、その上の複数のナノ構造と、ナノ構造にわたって配置される反射防止コーティングとを含んでもよい。反射防止コーティングは、透明ポリマー、例えば、フォトレジスト層であってもよく、ナノ構造の屈折率より低く、上層媒体（例えば、空気）の屈折率より高い、屈折率を有し得る。有利には、反射防止コーティングは、メタ表面が組み込まれる、拡張現実ディスプレイにおいて、残影画像を低減または排除させ得る。【選択図】図１０

Eyepieces for augmented reality display system

An eyepiece waveguide for an augmented reality display system. The eyepiece waveguide can include an optically transmissive substrate with an input coupling grating (ICG) region. The ICG region can receive a beam of light and couple the beam into the substrate in a guided propagation mode. The eyepiece waveguide can also include a combined pupil expander-extractor (CPE) grating region that receives the beam of light from the ICG region and alters the propagation direction of the beam with a first interaction and out-couples the beam with a second interaction. The diffractive features of the CPE grating region can be arranged in rows and columns of alternating higher and lower quadrilateral surfaces or the diffractive features can comprise diamond shaped raised ridges. The eyepiece waveguide can also include one or more recycler grating regions.

Metasurfaces with light-redirecting structures including multiple materials and methods for fabricating

Flat spectral response gratings using high index materials

An example head-mounted display device includes a plurality of optical elements in optical communication. The optical elements are configured to project an image in a field of view of a user wearing the head-mounted display device. A first optical element is configured to receive light from a second optical element. The first optical element defines a grating at along a periphery of the first optical element. The grating includes a plurality of protrusions extending from a base portion of the first optical element. The protrusions include a first material having a first optical dispersion profile for visible wavelengths of light. The grating also includes a second material disposed between at least some of the plurality of protrusions along the base portion of the first optical element. The second material has a second optical dispersion profile for visible wavelengths of light.

Pvh in-band chromatic correction using metasurface

An optical device includes an optical component (e.g., a polarization volume hologram, a geometric phase device, or a polarization-insensitive diffractive optical element) having a uniform thickness and configured to modify a wavefront of a light beam that includes light in two or more wavelengths visible to human eyes, where the optical component has a chromatic aberration between the two or more wavelengths. The optical device also includes a metasurface on the optical component. The metasurface includes a plurality of nanostructures configured to modify respective phases of incident light at a plurality of regions of the metasurface, where the plurality of nanostructures is configured to, at each region of the plurality of regions, add a respective phase delay for each of the two or more wavelengths to correct the chromatic aberration between the two or more wavelengths.

Multi-layer diffractive eyepiece

Disclosed is an eyepiece for projecting an image to an eye of a viewer, the eyepiece comprising: a planar waveguide configured to propagate light in a first wavelength range; a grating coupled to the planar waveguide and configured to diffract a first portion of the light propagating in the planar waveguide out of a plane of the planar waveguide toward a first direction and to diffract a second portion of the light out of the plane of the planar waveguide toward a second direction opposite to the first direction; a front cover plate disposed substantially parallel to and in front of the planar waveguide; and a wavelength selective reflector coupled to the front cover plate and configured to reflect light in the first wavelength range and transmit light outside the first wavelength range, such that the wavelength-selective reflector reflects at least part of the second portion of the light back toward the first direction.

Eyepieces for use in wearable display systems

An example a head-mounted display device includes a light projector and an eyepiece. The eyepiece is arranged to receive light from the light projector and direct the light to a user during use of the wearable display system. The eyepiece includes a waveguide having an edge positioned to receive light from the display light source module and couple the light into the waveguide. The waveguide includes a first surface and a second surface opposite the first surface. The waveguide includes several different regions, each having different grating structures configured to diffract light according to different sets of grating vectors.

Multi-layer diffractive eyepiece

Disclosed is an artifact mitigation system comprising: a projector assembly; a set of imaging optics optically coupled to the projector assembly; an eyepiece optically coupled to the set of imaging optics, wherein the eyepiece includes an incoupling interface; and an artifact prevention element disposed between the set of imaging optics and the eyepiece, the artifact prevention element including: a linear polarizer; a first quarter waveplate disposed adjacent the linear polarizer; a second quarter waveplate disposed between the linear polarizer and the set of imaging optics; and a color select component disposed adjacent the first quarter waveplate.

Pvh in-band chromatic correction using metasurface

An optical device includes an optical component (e.g., a polarization volume hologram, a geometric phase device, or a polarization-insensitive diffractive optical element) having a uniform thickness and configured to modify a wavefront of a light beam that includes light in two or more wavelengths visible to human eyes, where the optical component has a chromatic aberration between the two or more wavelengths. The optical device also includes a metasurface on the optical component. The metasurface includes a plurality of nanostructures configured to modify respective phases of incident light at a plurality of regions of the metasurface, where the plurality of nanostructures is configured to, at each region of the plurality of regions, add a respective phase delay for each of the two or more wavelengths to correct the chromatic aberration between the two or more wavelengths.

Detecting physical aspects of an eye using inward-facing sensors in an artificial reality headset

Methods, systems, and storage media for eye tracking in artificial reality (e.g., virtual reality, augmented reality, mixed reality, etc.) headsets are disclosed. Exemplary implementations may: generate a simulated environment for a user through an artificial reality headset; track an eye of the user through an eye sensor responsive to the artificial reality headset being worn by the user; detect a physical aspect of the eye through the eye sensor indicative of an eye malady; and adjust a display setting of the artificial reality headset based at least in part on the detected physical aspect of the eye.

Eyepieces for use in wearable display systems

An example a head-mounted display device includes a light projector and an eyepiece. The eyepiece is arranged to receive light from the light projector and direct the light to a user during use of the wearable display system. The eyepiece includes a waveguide having an edge positioned to receive light from the display light source module and couple the light into the waveguide. The waveguide includes a first surface and a second surface opposite the first surface. The waveguide includes several different regions, each having different grating structures configured to diffract light according to different sets of grating vectors.

Waveguide with polarization volume hologram grating

A waveguide is provided. The waveguide includes a substrate having two outer surfaces for propagating a beam of light in the substrate by reflecting the beam from the two outer surfaces. The waveguide includes at least one polarization volume hologram (PVH) grating to couple light in and/or out of the waveguide. The PVH grating may be a multi-layer PVH grating with graded birefringence.

Detecting physical aspects of an eye using inward-facing sensors in an artificial reality headset

Methods, systems, and storage media for eye tracking in artificial reality (e.g., virtual reality, augmented reality, mixed reality, etc.) headsets are disclosed. Exemplary implementations may: generate a simulated environment for a user through an artificial reality headset; track an eye of the user through an eye sensor responsive to the artificial reality headset being worn by the user; detect a physical aspect of the eye through the eye sensor indicative of an eye malady; and adjust a display setting of the artificial reality headset based at least in part on the detected physical aspect of the eye.

Eyepieces for augmented reality display system

Inline in-coupling optical elements

A display system includes a waveguide assembly having a plurality of waveguides, each waveguide associated with an in-coupling optical element configured to in-couple light into the associated waveguide. A projector outputs light from one or more spatially-separated pupils, and at least one of the pupils outputs light of two different ranges of wavelengths. The in-coupling optical elements for two or more waveguides are inline, e.g. vertically aligned, with each other so that the in-coupling optical elements are in the path of light of the two different ranges of wavelengths. The in-coupling optical element of a first waveguide selectively in-couples light of one range of wavelengths into the waveguide, while the in-coupling optical element of a second waveguide selectively in-couples light of another range of wavelengths. Absorptive color filters are provided forward of an in-coupling optical element to limit the propagation of undesired wavelengths of light to that in-coupling optical element.

Waveguide with polarization volume hologram grating

A waveguide is provided. The waveguide includes a substrate having two outer surfaces for propagating a beam of light in the substrate by reflecting the beam from the two outer surfaces. The waveguide includes at least one polarization volume hologram (PVH) grating to couple light in and/or out of the waveguide. The PVH grating may be a multi-layer PVH grating with graded birefringence.

Metasurfaces for redirecting light and methods for fabricating

A near-eye display system comprising: a waveguide for outputting image information; an optical element disposed on a surface of the waveguide, the optical element configured to in-couple or out-couple light for providing the image information, the optical element comprising: a multilevel metasurface comprising: a plurality of spaced-apart protrusions having a pitch and formed of a first optically transmissive material; and an optically transmissive resist between the spaced-apart protrusions. The use of a multi-level metasurface allows the use of relatively low refractive index materials, while providing highly wavelength selective redirection of light, including light in the visible part of optical spectrum. This makes the metasurfaces suitable for use in near-eye display systems, whilst avoiding issue with metasurfaces manufacture.

Metasurfaces with asymemtric gratings for redirecting light and methods for fabricating

Eyepieces for use in wearable display systems

An example a head-mounted display device includes a light projector and an eyepiece. The eyepiece is arranged to receive light from the light projector and direct the light to a user during use of the wearable display system. The eyepiece includes a waveguide having an edge positioned to receive light from the display light source module and couple the light into the waveguide. The waveguide includes a first surface and a second surface opposite the first surface. The waveguide includes several different regions, each having different grating structures configured to diffract light according to different sets of grating vectors.

Flat spectral response gratings using high index materials