Abstract: A method is provided for making a photonic band gap fiber including the steps of etching a preform and then drawing the preform into a photonic band gap fiber. Glass tubes are bundled and then formed into a photonic crystal perform having a number of passageways by reducing the cross-section of the bundle. One of the passageways is enlarged by flowing an etchant through it. After cleaning, the band gap fiber is made from the etched photonic preform, for example, by drawing.

Abstract: A laser gain medium and a method of manufacturing a laser medium, such as a laser rod, or slab for use in high-powered laser peening systems. A laser medium and method reduces stress risers along the surface of the amplifier medium by grit blasting, polishing, etching, annealing, and by eliminating platinum inclusions within the laser glass.

Abstract: A process for producing a waveguide, wherein a first layer is deposited on a silicon or glass substrate, a core structure is subsequently structured, and the core structure is protected by a protective layer. Prior to each step for depositing a new layer, the layer that has just been applied is fluorinated.

Abstract: The surface quality of halide, preferably fluoride, articles, e.g., articles used in the preparation of halide fibers is improved by cleaning the surface with an aqueous etchant and thereafter removing the etchant by washing the surface with methanol. The aqueous etchant is preferably a solution which contains hydrochloric acid and zirconium oxychloride.

Abstract: A method for drawing a mother ingot into a preform for optical fibers comprises providing a mother ingot, subjecting the mother ingot to measurement of a distribution of refractive index along radial directions thereof to determine a ratio of a core diameter to a clad diameter, and comparing the thus determined ratio with a predetermined ratio between the core diameter and the ingot diameter which ensures intended optical transmission characteristics, under which if the determined ratio is insufficient for the intended light transmission characteristics, the mother ingot is further processed until the predetermined ratio is substantially attained, and the resultant ingot is drawn to a preform, or if the determined ratio is acceptable on comparison with the predetermined ratio, the mother ingot is finally drawn.

Abstract: In a method of shrinking a tubular optical fiber preform with a doped silica core the preform is placed on a glassmaking lathe to rotate it about an axis, a torch is moved parallel to the axis in front of the preform to shrink it and collapse it in a number of passes, and during an etching pass a mixture of oxygen and a fluorine precursor gas is injected through one end of the incompletely collapsed preform to eliminate a certain layer from the core. During the etching pass, a certain value of the pressure of the gaseous mixture at the end of the preform is determined and the speed of the torch is slaved to this pressure value. Controlling the speed of the torch stabilizes the pressure of the gaseous mixture inside the preform, which longitudinally homogenizes the diameter of the core and the refractive index difference relative to an optical cladding around the core.

Abstract: A low-cost fabrication technique, readily extensible to volume manufacturing is presented for an electro-optically active fiber segment (31) that can be simply integrated into optoelectronic devices. The fabrication technique offers a dielectric isolation structure (16, 17) surrounding the fiber (10) to allow high field poling, a pair of electrodes (37, 38) used both for poling and for inducing an electro-optic effect, and ends of the fiber (18, 19) unaffected by the fabrication and available for splicing with additional fiber sections. The technique is readily adaptable to specialized electrode structures including striplines and/or microstrip lines for high frequency applications and segmented electrodes (52) for quasi-phasematched three-wave mixing applications. By combining the electro-optically active fiber segment (31) with other fibers in an integrated fiber modulator, high frequency modulation of an optical signal may be achieved with applications in telecommunications.

Abstract: A method for manufacturing a glass preform from a metal sulfide chalcogenide glass to which a large amount of light emitting substances can be added includes steps of etching a surface made of the chalcogenide glass or oxychalcogenide glass of disc shape core and clad forming glass starting materials by an etchant including an acid and a compound reacting with a hydrogen chalcogenide, and forming the core forming glass starting material and the clad forming glass starting material into a united body serving as a glass preform. In a method for manufacturing a single-mode glass fiber using a preform method by drawing the glass preform whose outer round surface is made of a chalcogenide glass or oxychalcogenide glass, the outer round surface of the glass preform is etched using an etchant including an acid and a compound reacting with a hydrogen chalcogenide and then drawn into the glass fiber.

Abstract: The specification describes techniques for chemically machining extruded glass preforms used to draw glass ferrules for optical fiber connectors. Using the chemical machining technique the dimensions of the preform, including OD, ID, and the OD to ID ratio can be adjusted so that the dimensions of drawn ferrules meet strict dimensional standards. The technique is especially useful for adjusting the dimensions of extruded preforms that have an inherent bow along in the length of the preform. The technique allows adjustment in dimensions while preserving a desired OD to ID ratio. Also described are techniques for reducing eccentricity and/or ellipticity of hollow bore glass preforms.

Abstract: A quartz glass tube, produced by mechanically processing a natural/synthetic quartz glass mother material, having 50-300 mm.phi. in outer diameter, from. 1 to 7 in outer to inner diameter ratio, 10 mm or more in thickness and 2% or less in thickness error; a large-scale quartz glass preform integrally combining the large-sized quartz glass tube with a core glass rod for an optical fiber using a rod-in-tube technique; and a method for manufacturing a large-scale quartz glass preform performing the mechanical processing with a high precision machine, i.e., integrating a core rod for an optical fiber under a rod in process with a quartz glass tube, a tube diameter of which is controlled by heating, hot drawing or hot drawing with pressure by using a tool-free drawing method.

Abstract: This invention involves a fiber probe device and a method of making it. The probe includes a relatively thick upper cylindrical region, typically in the form of a solid right circular cylinder, terminating in a tapered region that terminates in a relatively thin lower cylindrical region (tip), typically also in the form of a solid right circular cylinder, the lower region having a width (diameter) in the approximate range 0.01 .mu.m to 150 .mu.m.

Abstract: An optical fiber glass preform is preheated so that it is uniformly preheated therethrough, then a surface of the preform is abraded by an oxyhydrogen flame to obtain a smooth optical fiber glass preform. This method is advantageous when relatively larger diameter preforms are treated in this manner because the step of uniformly preheating the preform reduces or eliminates a temperature differential therein. The temperature differential could otherwise cause the preform to crack during cooling.

Abstract: A method of improving the symmetry of a cylindrical silica tube to be used in making a preform having a circular outside surface eccentric to a circular inside surface thereby providing a varying tube thickness throughout the circumference of the tube which includes the following steps. The first step is locating a longitudinal generator line of the cylindrical tube at a greatest thickness of the tube at a given circumferential point on the tube, and while preventing the tube from rotating, etching in at least one pass the inside of the tube with a gas capable of decomposing silica, while heating the outside of the tube along that longitudinal generator line.

Abstract: Fluoride glass optical fibers are fabricated by minimizing the number of high-temperature operations. A tube comprising an external layer of a first fluoride glass of composition suitable to form the cladding of the fiber and an internal layer of a second fluoride glass of composition suitable to form the core of the fiber is prepared by a conventional rotational casting technique. Then, the internal layer is thinned by means of chemical etching at ambient temperature until the attainment of a ratio between the volumes of the two layers that corresponds to the ratio between the core and cladding diameters required for a single mode fiber, and the resulting tube is drawn.

Abstract: The surface quality of halide, preferably fluoride, articles, e.g. articles used in the preparation of halide fibres is improved by cleaning the surface with an aqueous etchant and thereafter removing the etchant by washing the surface with methanol. The aqueous etchant is preferably a solution which contains hydrochloric acid and zirconium oxychloride.

Abstract: A low-cost fabrication technique, readily extensible to volume manufacturing is presented for an electrooptically active fiber segment that can be simply integrated into optoelectronic devices. The fabrication technique offers a dielectric isolation structure surrounding the fiber to allow high field poling, a pair of electrodes used both for poling and for inducing an electrooptic effect, and ends of the fiber unaffected by the fabrication and available for splicing with additional fiber sections. The technique is readily adaptable to specialized electrode structures including striplines and/or microstrip lines for high frequency applications and segmented electrodes for quasi-phasematched three-wave mixing applications. By combining the electrooptically active fiber segment with other fibers in an integrated fiber modulator, high frequency modulation of an optical signal may be achieved with applications in telecommunications.

Abstract: This invention involves a fiber probe device and a method of making it. The probe includes a relatively thick upper cylindrical portion, typically in the form of a solid fight circular cylinder, terminating in a tapered portion that terminates in a relatively thin lower cylindrical portion, typically also in the form of a solid right circular cylinder, the lower portion having a width (diameter) in the approximate range of as little as approximately 0.05 .mu.m.

Abstract: A process for forming film structure using Flame Hydrolysis Deposition (FHD) in which (1) glass soot is deposited on a substrate via FHD to form a first porous vitreous layer having a first bulk density, (2) a second porous vitreous layer having a second bulk density that is larger than the first bulk density is formed from a portion of the first porous vitreous layer, and (3) a third porous vitreous layer having a third bulk density is formed by depositing glass soot containing a refractive index increasing dopant on the second porous vitreous layer by FHD. The first, second and third porous vitreous layers are then heated to form an undercladding layer and a core layer, the undercladding layer being formed from the first and second porous vitreous layers and the core layer being formed from the third porous vitreous layer.

Abstract: A glass preform for an optical fiber is flame abrased with an oxyhydrogen flame while vertically suspending and rotating the glass preform and relatively moving one or both of the glass preform and the oxyhydrogen flame, whereby a surface of the glass preform is smoothened.