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: An optical micro-machining method of glass characterized in that after light is applied to glass including SiO.sub.2 and 30-70 mol % GeO.sub.2, the irradiated area is removed by etching.

Abstract: A porous body containing a silicon component as a starting material of optical element is immersed in a solution containing hydrofluoric acid, taken out from the solution and immersed in a solution containing a metal alkoxide containing a first metal component except silicon or a derivative thereof so that the porous body contains the first metal component in such a concentration gradient that the concentration of the first metal component decreases from a periphery of the porous body toward a center of the porous body. Hydrofluoric acid breaks glass bonds of the porous body, so that the concentration of the first metal component can be securely distributed in a desired gradient. Drying and sintering of the porous body enables producing, for example, a glass having a metal component concentration concavely distributed in its radial direction which is excellent in chromatic aberration suppressing capability.

Abstract: A method and apparatus for treating a surface on a glass article with a fluid. The article is surrounded by a containment system for the treating fluid and the fluid is continuously agitated by an agitator.

Abstract: Methods of manufacturing optical elements such as diffraction type lenses, aspherical lenses and diffraction gratings are disclosed. Deposited on a glass substrate is a workpiece film made of a material which can be machined much more easily than the substrate. Then the workpiece film is machined to form a predetermined shape or contour therein. After forming the predetermined shape or contour in the workpiece film, the workpiece film and substrate are subjected to etching to duplicate the predetermined shape or contour formed in the workpiece film into the substrate.

Abstract: The invention provides a process for making a gradient index optical element having a precisely parabolic configuration of refractive index profile. After a concentration profile is imparted across a gel prepared by a sol-gel technique, the concentration profile is fixed. In this case, the treatment with a concentration profile-fixing solution is carried out at a temperature higher than that at which the treatment with a concentration profile-imparting solution is carried out, whereby the rate of fixing the concentration profile is so higher than that of imparting the concentration profile, so that any possible deformation of the concentration profile formed at the concentration profile-imparting step is reduced or inhibited.

Abstract: The invention relates to a process for reinforcing a glass object by precompressing the surface of the object, acid etching said surface to a depth equal to or less than the compressed depth of the glass, and finally protecting the etched surface.

Abstract: A method for fabricating a large-sized primary treated quartz glass tube by perforating a cylindrical quartz glass mother material by a hot carbon drill press-in-process followed by etching and washing. The large-sized primary treated quartz glass tube is converted to a large-sized quartz glass preform by combining it with a core glass rod for an optical fiber. Another embodiment is a method for fabricating a large-sized quartz glass tube by heating, hot drawing or hot drawing under pressure using a tool-free drawing method under control of an inside pressure of the large-sized primary treated quartz glass tube at a temperature ranging from 1600.degree. C. to 3000.degree. C. to satisfy a specific equation.

Abstract: In the measurement of internal transmittance of optical pieces, a standard is set for the piece for measuring the transmittance and a method of making the piece is provided. In the piece for measuring the transmittance of optical materials having two opposing polished surfaces, their surface roughness rms is set to 10 .ANG. or less, thereby making it possible to accurately measure the internal transmittance in the short wavelength region of 300 nm or less where the intensity of the light source of spectrophotometer begins to decrease.

Abstract: A glass substrate manufacturing method advantageously applicable to magnetic recording disk glass substrates, LCD glass substrates, photomask glass substrates, or optical memory glass substrates. The glass substrate is formed by chemically strengthening a glass substrate by immersing the glass substrate in a chemical reinforcement solution heated and then ion exchanging ions on the surface layer of the glass substrate with ions in the chemical reinforcement solution; removing the substrate from the chemical reinforcement solution and then annealing it to a temperature higher than the crystallization temperature of a molten salt; rapidly cooling the glass substrate at a rate at which the crystallization of the molten salt deposited on the surface of the glass substrate is prevented; and then cleaning the surface of the glass substrate.

Abstract: An optical lens element is produced by the following steps of:preparing a glass pre-form;forming a metal thin layer or a powder layer, said metal thin layer including gold, platinum, rhodium, nickel, or palladium; andpressing the glass pre-form with the metal thin layer against molding surfaces to form the optical lens element.

Abstract: In accordance with the invention, a continuously chirped fiber Bragg grating is made by fabricating a continuously chirped phase mask and using the mask to write a Bragg grating on a parallel fiber. The chirped phase mask is made by exposing a photoresist-coated mask substrate to two interfering beams: one a collimated beam and the other a beam reflected from a continuously curved mirror. After etching, the resulting phase mask can be used to write a chirped fiber grating having a continuously varying grating period without physical modification of the fiber. The resulting fiber grating has a widened bandwidth and uniform dispersive delay characteristics useful for dispersion compensation in critical telecommunications applications.

Abstract: A method for dissolving silica-rich fibers such as borosilicate fibers, fiberglass and asbestos to stabilize them for disposal. The method comprises (1) immersing the fibers in hot, five-weight-percent sodium hydroxide solution until the concentration of dissolved silica reaches equilibrium and a only a residue is left (about 48 hours), then immersing the residue in hot, five-weight-percent nitric acid until the residue dissolves (about 96 hours). After adjusting the pH of the dissolved fibers to be caustic, the solution can then be added to a waste vitrification stream for safe disposal. The method is useful in disposing contaminated HEME and HEPA filters.

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: 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 right 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 glass material is formed from SiO.sub.2, CaO, Na.sub.2 O and P.sub.2 O.sub.5 and the porous, non-crystalline structure is most preferably created by melting the constituents, cooling and pulverizing the resulting glass, and then forming and hot pressing the powder. The glass of the present invention may be formed to produce templates that are useful for various indications, as well as granules that may be formed into a paste.

Abstract: The method for forming a tip of an array optical fiber disclosed is one in which an etching resistive material such as a photoresist is applied first on an end portion of a coated material covering constituent fibers of the array optical fiber, and then the ends of the constituent fibers are etched. Due to the presence of the etching resistive material, the etching solution does not dissolve the coated material. In an alternative method, the etching resistive material such as a photoresist is applied on a side surface of a tip portion of each constituent fiber of the array optical fiber exposed from the coated material, the tip portion is cut and flattened together with the etching resistive material, and the end faces of the constituent optical fibers are etched. The presence of the etching resistive material prevents the tip diameter of the constituent optical fiber from becoming small.

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: A method is disclosed for producing an ink jet print head which both realizes a higher density and prevents a failure in ink jetting and deterioration in the printing quality. A multiplicity of individual ink passages, each having an narrow width and a large depth, are formed in an array by anisotropic etching a photosensitive glass substrate. A diaphragm is attached to the surface of the glass substrate so as to cover the individual ink passages. A common electrode is provided on the diaphragm, and individual piezoelectric elements are fixed to the common electrode at the portions corresponding to the individual ink passages. Individual electrodes are provided on the respective individual piezoelectric elements. A voltage applied to the common electrode and an individual electrode causes a portion of the diaphragm to corresponding to the individual electrode to be bend and deformed. The ink storing capacity of the corresponding individual ink passage is reduced and some of the ink is forced out.

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: Proposed is an efficient method for the preparation of vitreous hollow microspheres from particles of a vitreous volcanic deposit by a heat treatment to effect expansion of the particles by foaming. The inventive method comprises a step, prior to the heat treatment for expansion of the particles, in which the starting particles are dispersed in an aqueous medium containing aluminum sulfate and urea each in a specified concentration followed by a heating treatment of the dispersion so as to deposit a coating layer of aluminum hydroxide on the particle surface so that the efficiency of foaming can be greatly improved without the disadvantage of particle agglomeration.

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: 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: A method of producing an elliptic core type polarization-maintaining optical fiber comprises the steps of providing a glass rod comprising a cladding glass layer around the periphery of a core glass layer, the cladding glass layer having a softening point higher than the softening point of the core glass layer, removing two side surface portions of the glass rod by machining along the axial direction of the glass rod to form a machined rod noncircular in cross section, outside depositing fine silica glass particles on the periphery of the machined rod, followed by sintering to provide a support glass layer having a softening point higher than the softening point of the cladding glass layer, and drawing the thus obtained glass rod body as an optical fiber preform. Since the portion for constituting the core of the optical fiber is formed by machining, the core is permitted to have a high ellipticity.

Abstract: A method for manufacturing a glass is provided, comprising converting a porous body to a multi-component glass, wherein a porous body containing at least one metal component in the form of a metal salt is immersed in a solution containing at least one compound selected from the group consisting of an acid, an ammonium salt and an alkylammonium salt to precipitate the metal salt as microcrystals in the pore. Also, a method for manufacturing a glass for use as a gradient index optical element is provided, comprising converting a porous body to a multi-component glass, wherein a porous body containing at least one metal component in the form of a metal salt is immersed in a solution containing a salt of a metal component different from the above-mentioned at least one component and at least one compound selected from the group consisting of an acid and a salt to provide the metal components with concentration distributions.

Abstract: Quartz sections having a surface condition as polished as possible are prepared by controlled dissolution by placing said quartz sections in a bath of a quartz solvent or a mixture of solvents, wherein the bath is basic and comprises an alkaline hydroxide or fluoride, or ammonium hydroxide, or a mixture of these compounds; and conducting controlled dissolution of the quartz sections at atmospheric pressure.

Abstract: An optical waveguide is made by forming successively of light transmitting material a first clad layer (13), a core layer (15) and a second clad layer (18). The core layer has a higher refractive index than that of the first and second clad layers such that the core layer (15) can transmit light along its length as an optical waveguide. A sacrificial layer (14, 17) is formed surrounding at least a first end potion of the core layer. The sacrificial layer is selectively removed as by selective etching such that the first end portion of the core layer is separated from the first and second clad layers. With the end portion so isolated, a lens (22) can be formed on it such that light may be more effectively coupled to or from the core layer. Preferably, the lens is formed by heating the structure sufficiently to form a meniscus on the free end and then cooling it before the reminder of the core layer flows or melts. The cooling hardens the meniscus such that it constitutes an optical lens.

Abstract: A method of processing a photosensitive glass includes exposing. Photosensitive glass by radiation from a laser whose oscillation wavelength lies within the range of wavelengths of exposing light to which the glass responds. Then, the exposed portions 1c are thermally developed and etched. Since a laser beam propagates with a high rectilinearity, the front and rear surfaces of thick photosensitive glass can be exposed without producing dimensional errors. Therefore, the etching accuracy is improved. Especially, where the front and rear surfaces of photosensitive glass are etched, both surfaces can be processed so as to form the same shape in them accurately. In addition, because almost all the energy of the laser radiation is used for exposure of the photosensitive glass, the energy is not wasted and so the efficiency is high.

Abstract: A method is described for reducing the lead and/or barium emission of articles of crystal glass containing lead and/or barium, particularly so-called lead crystal and baryte glasses, on contact with a liquid phase, particularly aqueous, aqueous-acidic, alcoholic and aqueous-alcoholic liquids such as acetic acid solutions, wine, whiskey, liqueurs and the like, with the crystal glass objects being treated, if applicable before and/or after acid polishing, with 5 to 45% by weight of an alkali hydroxide solution at a temperature of 20.degree. to 60.degree. C.

Abstract: Glass free of surface carbon deposits, such as carbon film and/or carbon occlusions, and a process for removing such carbon deposits from glass. The process is characterized by the application of a plasma to glass to remove the carbon deposits. The plasma used for this purpose contains active specie which reacts with the carbon deposits to form gaseous carbon products.

Abstract: This invention is directed to a method for preparing glass sheet having surfaces which are essentially defect-free and equivalent in smoothness to polished glass surfaces which comprises the steps of: Two different batches of alkali-metal-free batches are melted and formed into a laminated sheet and the first glass is enclosed by the second glass. The second glass is 1000 times more soluble than the first glass. The laminate is contacted with an acid to dissolve the second glass wherein the first glass remains with essentially defect free surfaces.

Abstract: A photosensitive glass processing method, and article made thereby, which makes it possible to facilitate the etch depth control, minimize the surface roughness of the etched surface, improve the operating efficiency in single-side etching process, and increase the yield includes a first exposure step, in which laser light is applied to the obverse side of photosensitive glass from above it through an exposure mask by using a pulsed laser that covers the sensitivity wavelength range of the photosensitive glass, thereby forming a first exposed portion, the energy intensity per pulse of laser light being set at 10 mJ/cm.sup.2, and the total exposure energy being set at 500 mJ/cm.sup.2 ; a second exposure step, in which laser light is applied to an end surface of the photosensitive glass through another exposure mask, thereby forming a second exposed portion, the energy intensity per pulse of laser light being set at 10 mJ/cm.sup.2, and the total exposure energy being set at 15,000 mJ/cm.sup.

Abstract: Method of processing a photosensitive glass used in the head of an ink jet printer, including the steps of exposing the glass by a XeCl excimer laser to write a desired pattern into the front surface of the glass, with the laser emitting plural pulses to the glass and the energy of each laser pulse being 1 to 50 mJ/cm.sup.2 such that the exposed portions which will become crystallized portions do not extend through the thickness of the glass; thermally developing the exposed portions to crystallize the exposed portions; and etching away the crystallized portions so that grooves are formed in the glass according to the exposing pattern.

Abstract: The present invention relates to a process for making glass by the sol-gel process. A mixture of silicon alkoxide, at least two other metal alkoxides, and alcohol in a solution sufficiently acidic to hydrolyze partially the silicon alkoxide is formed. Water is then added under agitation to convert the metal alkoxides to a network of corresponding metal oxides suitable for gelation. The mixture containing the network of metal oxides is then molded for a sufficient time to form a gel. Substantially only oxides of one of the at least two other metals is then removed from the gel, which is then fixed in a liquid capable of arresting such additional removal. The fixed gel is then dried and sintered to form a glass. The step of removing the at least one other metal oxide from the gel can be followed with a step of withdrawing partially oxides of one of the remaining at least two other metals in order to form a transparent gradient-index glass after sintering.

Abstract: A method for fabricating a waveguide type optical device is disclosed, through which a core and a reference plane are obtained at the same time by etching a core layer using a thin layer of a predetermined shape formed on the core layer as a mask. In this waveguide type optical device, the core is easily coupled with an optical element such as an optical fiber by means of the reference plane.

Abstract: A method of producing dealkalized sheet glass in which sheet glass is dealkalized in stages. The method includes dealkalizing sheet glass in a first stage by exposing the sheet glass to contact with a first dealkalizing medium including at least one acid gas for a period of at least 1 minute while the sheet glass is at a temperature above 400.degree. C.; and further dealkalizing the sheet glass in a subsequent stage by exposing the sheet glass after the first stage to contact with a second dealkalizing medium including at least one acid gas for a period of at least 3 minutes while the sheet glass is at a temperature which is at least 50.degree. C. below one of the temperature of the sheet glass during the first stage and the minimum temperature of the sheet glass during the first stage, and ranges between 400.degree. C. and 250.degree. C.

Abstract: A Si--SiC ceramic layer is bonded to a non-porous SiC substrate with the Si etched from the layer to form a relatively porous surface on the otherwise non-porous high strength SiC substrate. A quartz layer is softened by heating and forced into the pores of the porous layer to form a mechanical bond to the SiC substrate. A refractory metal layer is bonded to the quartz layer to complete the joint. A refractory metal support component is then bonded to the refractory layer whereby the quartz serves as a high strength, high temperature reaction barrier between the metal of the refractory layer and the silicon of the SiC substrate.

Abstract: The end region of a fiber optic sensor is tapered by suspending a fiber in a container. Etchant is added to the container at a controlled rate in order to etch a taper into the fiber. The taper size and shape are controlled by the selection of the size and shape of the container, as well as by the rate of adding etchant to the container.

Abstract: A method for manufacturing waveguide-type optical components featuring a lower propagation loss at low cost in which a lower clad section (2) made of silica glass is formed on a substrate (1), and an antistatic layer and a mask layer having a desired pattern are formed on the surface of the lower clad section (2) in the order they are listed. Then, an electron beam is irradiated from above the mask layer to produce a core (6) of the desired pattern in the lower clad section (2), the mask layer and the antistatic layer are removed to expose the surface of the lower clad section (2), and an upper clad section (7) having a lower refractive index than the core (6) is formed on the exposed surface of the lower clad section (2), thus producing an optical component. The surface of the whole optical component is at a distance from the core; therefore, the scattering loss caused by minute irregularities on the surface of the optical component is reduced.

Abstract: The present invention provides an improved glass etching composition which does not contain any causative materials such as hydrofluoric acid, causing environmental pollution. The etching composition comprises a first solution of a flow modifier and ammonium bifluoride in purified glycerine; and a second solution of ammonium bifluoride and ferric chloride in purified glycerine.

Abstract: A method for making a semi-permeable microporous polymer sheet, useful as a separation membrane or the like, including extruding a melt-blended mixture of a high-temperature thermoplastic polymer and a leachable glass to form sheet and then leaching the glass from the sheet to leave a microporous relict polymer network, wherein the permeability of the sheet is improved by plasma-etching the surface of the sheet before or after leaching. Hydrophilic or hydrophobic porous membranes may be provided.

Abstract: A process for producing decorated glass-ceramic articles is described in which an article of crystallizable glass, prior to being decorated with a ceramic color and then converted into a glass-ceramic article by heat treatment with simultaneous burning-in of the ceramic color, is pre-heat treated with a Bronsted acid at temperatures between 50.degree. and 800.degree. C. until the surface layer of the glass article is modified so that the layer of ceramic color sinks into the surface of the article during burning-in/ceramicizing, thereby permitting if desired, a thicker layer of ceramic color to be applied and the production of decorated glass-ceramic articles in which the decoration is flush with the surface of the article to be produced, thereby reducing its susceptibility to damage and wear.

Abstract: The present invention relates to a process of producing a magnetic disk substrate comprising etching the surface of a glass substrate to form minute irregularities on the surface thereof, by employing the molten salt containing at least a kind of nitrite of cation, which process can prevent the deterioration of the mechanical property and magnetic property of the glass sabstrate for use as a magnetic disk for a long time.

Abstract: The present invention provides a method of forming a semiconductor device mprising the steps of:forming a glass block of an acid inert glass having acid etchable glass rods extending therethrough, the acid etchable glass rods having an average diameter of less than 1 micron;partially etching one end of the acid etchable rods surface of the glass block to form cavities in the glass block on one surface thereof having an average diameter of less than 1 micron;depositing material(s) in the cavities to form a semiconductor device.The present invention also provides a method for forming a semiconductor device in which the acid etchable glass rods are completely etched and the deposition material(s) is deposited to fill the nanochannels formed by the etching.The present invention also provides semiconductor devices made by these methods.

Abstract: A method of manufacturing distributed index optical elements is disclosed. The method comprises a step of preparing silica sol including at least one of metal dopants, a step of dipping, after subjecting the silica sol to a gelling treatment, the silica gel in an elute into which a part of metal constituents other than silicon including in the gel is selectively eluted, and a step of drying and sintering the silica gel.

Abstract: In a glass front-panel for a cathode ray tube, whose surface layer contains more potassium ions than those in the interior thereof, and whose flange is stuck to a rear panel to form a vacuum vessel, only the surface layer of the flange portion is substantially removed, or in a glass front-panel for a cathode ray tube, comprising an image displaying portion, a side wall portion and a flange portion, a belt-like electrode for making a gradient of electric potential easier is disposed on a surface of the side wall portion, so that the cathode ray tube is prevented from being damaged due to dielectric breakdown.

Abstract: A porous glass optical fiber sensor, a method for its use, and a method for its manufacture. The sensor includes a glass optical fiber for conveying light, the fiber having a surface of interconnected and permeable chambers within the fiber, for optically sensing within the chambers. An indicator can be applied to the surface for sensing. The sensor is made by: first, drawing the fiber; second, heat treating the fiber to induce phase separation; and third, leaching a phase from the fiber. Thereafter, an indicator, such as a pH or moisture indicator, can be applied to the fiber for sensing. The sensor is used in conjunction with a light source, a light detector, and means for measuring change in the light caused by an agent within the porosity of the sensor.

Abstract: A hermetically coated optical fiber comprising a core made of glass, a cladding made of quartz glass surrounding the core the outermost layer of which glass contains fluorine, and a carbon layer surrounding the fluorine-containing glass layer, which optical fiber has good initial strength and fatigue characteristics.

Abstract: This method is directed at a method for making selectively sculptured lithium silicate crystal-containing glass articles. A photonucleable, glass body is selectively exposed to short wave radiation and then heat treated to cause the development of crystals in those areas of the glass body which had been exposed to shortwave radiation. Those crystal-containing areas are then removed by acid etching and the resulting sculptured glass articles are thereafter exposed to short wave radiation and subsequently heat treated to obtain a degree of crystallization.The inventive method further comprises an improvement step of fabricating glass articles that result in crystal-containing glass articles with smaller intermediate dimensions than the desired final dimensions and subjecting the crystal-containing glass articles to an ion exchange process which exchanges potassium ions for sodium and/or lithium ions at a temperature of about at least 500.degree. C.

Abstract: A wavelength conversion device exhibiting an excellent wavelength conversion efficiency is provided by forming it in such a manner that an LiTaO.sub.3 substrate is subjected to a proton exchange treatment to form a proton-exchange layer before the proton-exchange layer is subjected to heat treatment to form a domain-inverted structure. Heat treatment is performed at a high temperature rising speed to prevent the thermal diffusion of the proton-exchange layer so that the expansion of the domain-inverted structure to be formed in the proton-exchange layer is restrained. As a result, a higher harmonic wave wavelength conversion device can be provided.