Rotary variable optical tap

Method and apparatus wherein continuous indexed lengths of optical fiber are automatically measured for load at failure for each failure below a predetermined maximum stress. A predetermined length of optical fiber is indexed. The optical fiber is clamped at one or more clamp points along its length. Increasing tension is applied to a first indexed length of optical fiber between at least one clamp point and a tension application means. Increasing tension is applied between an initial value and the predetermined maximum load. The increasing tension is measured during its application. If failure occurs, the actual load at failure is detected while the increasing tension is being applied. When failure does not occur, the first length of optical fiber is released and a second length of optical fiber is indexed to the position where increasing tension is applied to the second length between at least one clamp point and the tension application means.

Dispersion managed optical waveguide

Method of making fluorine/boron doped silica tubes

Abstract of the Disclosure Disclosed is a method of forming a glass tube doped with boron and fluorine. A B2O3-doped tubular porous preform is heated, and a fluorine-containing gas is flowed into its aperture. The temperature is sufficiently high to cause the fluorine-containing gas to decompose and form fluorine which dopes the preform. Also flowed into the aperture is a sufficient amount of BF3 to prevent fluorine from reacting with the B2O3 in the porous preform and forming a B2O3-depleted region near the aperture surface. The particles are then fused to form a fluorine-containing dense glass tube.

PROCESSES FOR PRODUCTION OF HIGH PURITY GLASS ARTICLES SUCH AS PARTICULATE GLASS PREFORM, PARTICULATE GLASS PREFORM AND OPTICAL WAVEGUIDE MOLDED THEREOF.

A method of making solid glass articles by the flame hydrolysis technique. A thin stratum of low viscosity glass soot is applied to the surface of a mandrel. First and second coatings of glass soot are deposited on the surface of the thin stratum to form a porous preform. The refractive index of the soot particles of the first coating is greater than that of the soot of the second coating, and the soot of the first coating has a viscosity lower than that of the second coating. The mandrel is removed, and the soot preform is subjected to a high temperature whereby it is consolidated to form a dense glass blank. The glass surface tension and the relative viscosities of the inner and outer portions of the preform cause the aperture to close during the consolidation process. The thin stratum, which preferably includes P2O5, smoothes over the damage caused by removing the mandrel and reduces or even eliminates seed formation at the axis of the resultant glass blank. The blank may be heated and drawn into a filament, or it may be sliced into optical windows, lenses or the like.