Abstract: A method for forming an optical quality glass is provided. The method includes contacting silica soot particles with a basic additive, forming a silica soot compact, and removing the basic additive from the silica soot compact. A method of forming a cladding portion of an optical fiber preform is also provided.

Abstract: A siliceous film having high purity and a low etching rate is formed by (a) a step for forming a siliceous film on a substrate by coating a solution composed of a polysilazane, e.g., perhydropolysilazane on a substrate and then hardening (curing) the solution in an oxidizing atmosphere, or by coating a silica solution formed by a sol-gel method on a substrate, and (b) a step for heating the siliceous film in an inert gas environment containing a nitrogen-containing compound such as an alkylamine having a base dissociation constant (pKb) no greater than 4.5, or a halogen-containing compound in which the bond energy of a halogen atom such as F2, Br2, or NF3 is no greater than 60 kcal/mol, in order to anneal the film.

Abstract: High aspect ratio core optical fiber designs, which could be semi-guiding, including a core region having a first refractive index and a high aspect ratio elongated cross-section along a slow axis direction, are described. An internal cladding having a second refractive index sandwiches the core and acts as a fast-axis signal cladding. The core has an edge region at both of its short edges that is in contract with edge-cladding regions having a barbell shape. The refractive index of the core regions, the refractive index of the internal claddings, and the refractive index of the edge-cladding regions, are selected so as to maximize the optical power of a lowest-order mode propagating in the fiber core, and to minimize the optical power of the next-order modes in the fiber core. A process to fabricate such a high aspect ratio core fiber is also provided.

Abstract: An optical sensor device includes an optical waveguide portion having a core, the core having a first refractive index, and a functional material layer coupled to the optical fiber portion, the functional material layer being made of a metal oxide material, the functional material layer being structured to have a second refractive index, the second refractive index being less than the first refractive index. The functional material layer may be a nanostructure material comprising the metal oxide material with a plurality of holes or voids formed therein such that the functional material layer is caused to have the second refractive index.

Abstract: [Object] In manufacturing a GRIN lens by a sol-gel method, an operation for preparing a wet gel is facilitated and cracking in a base material during sintering and foaming during drawing are prevented. [Solution] The object is achieved by obtaining a GRIN lens by producing a wet gel from an alcohol solution containing a silicon alkoxide, a dopant alkoxide, and a boron alkoxide as the main ingredients, leaching the same, drying the same to form a dry gel, and sintering and drawing the same.

Abstract: The present invention relates to a method for producing synthetic quartz glass, comprising the steps of: (A) providing a liquid SiO2 feedstock material (105), which comprises more than 70% by wt. of the polyalkylsiloxane D4, (B) vaporizing the SiO2 feedstock material (105) into a gaseous SiO2 feedstock vapor (107), (C) converting the SiO2 feedstock vapor (107) into SiO2 particles, (D) depositing the SiO2 particles on a deposition surface (160) while forming a SiO2 soot body (200), (E) vitrifying the SiO2 soot body (200) while forming the synthetic quartz glass, According to the invention it is provided that vaporizing the heated SiO2 feedstock material (105) comprises an injection phase in an expansion chamber (125) in which the SiO2 feedstock material (105) is atomized into fine droplets, the droplets having a mean diameter of less than 5 ?m, preferably less than 2 ?m.

Abstract: A method is provided for forming an optical fiber amplifier. The method comprises providing a composite preform having a gain material core that includes one or more acoustic velocity varying dopants to provide a longitudinally varying acoustic velocity profile along the gain material core to suppress Stimulated Brillouin Scattering (SBS) effects by raising the SBS threshold and drawing the composite preform to form the optical fiber amplifier.

Abstract: The present invention provides a hologram recording material which is suitable for volume hologram record and attains high refractive index change, flexibility, high sensitivity, low scattering, environment resistance, durability, low shrinkage and high multiplicity in holographic memory record using not only a green laser but also a blue laser; a process for producing the same; and a hologram recording medium having the hologram recording material. A hologram recording material comprising: a metal oxide containing at least Si and Zr as metals wherein a ?-dicarbonyl compound is coordinated to Zr; and a photopolymerizable compound, wherein a mole ratio of the ?-dicarbonyl compound to the Zr atom (?-dicarbonyl compound/Zr ratio) is 2/1 or more and 3/1 or less, and a mole ratio of the Si atom to the Zr atom (Si/Zr ratio) is more than 1/1 and 1.15/1 or less in the metal oxide. A hologram recording medium (11) comprising the hologram recording material layer (21).

Abstract: The present invention relates to an optical substrate comprising a transparent substrate, a low refractive index layer, whose refractive index is lower than that of the transparent substrate, disposed over the transparent substrate, and a solgel film disposed over the low refractive index layer; a light emitting element having a first electrode, a light emitting layer and a second electrode over the solgel film of this optical substrate; and a display device provided with this light emitting element.

Abstract: In a production process of an organic-inorganic hybrid glassy material, the invention relates to a process for producing an organic-inorganic hybrid glassy material, characterized in that the process comprises at least the three steps of producing a gel body by a sol-gel method; melting by heating; and aging, and it relates to an organic-inorganic hybrid glassy material produced by this process.

Abstract: A method is provided for forming an optical fiber amplifier. The method comprises providing a composite preform having a gain material core that includes one or more acoustic velocity varying dopants to provide a longitudinally varying acoustic velocity profile along the gain material core to suppress Stimulated Brillouin Scattering (SBS) effects by raising the SBS threshold and drawing the composite preform to form the optical fiber amplifier.

Abstract: An intermediate preform is formed in a process of manufacturing an optical fibre by forming a sol containing a glass precursor; pouring the sol in a mold containing a set of elongate elements; aging the sol to obtain a gel body; removing the set of elongate elements from the gel body to create a corresponding set of holes in the gel body; and removing the gel body from the mold. The method further provides imparting a motion of the set of elongate elements during aging of the sol to avoid adhesion of the gel to the elongate elements, the motion being preferably a rotation about the respective axes or an alternate translation along the respective axes. An apparatus with means for carrying out the method is also described.

Abstract: In a process for manufacturing a micro-structured optical fibre, an intermediate preform is made by forming a sol; pouring the sol in a cylindrical mould including a set of structural generating elements defining internal structural elements of the intermediate preform; transforming the sol into a gel so as to obtain a cylindrical gel body defining the intermediate preform; and removing the cylindrical intermediate preform from the mould.

Abstract: Inorganic fibers consisting substantially of silicon, carbon, oxygen and a transition metal, having a fiber size of no greater than 2 ?m and having fiber lengths of 100 ?m or greater.

Abstract: Carbon particles, such as, carbon fibrils and carbon nanotube molecules, are assembled into aligned fibers using processes derived from the processes used to manufacture optical fiber. More particularly, the carbon particles are embedded in glass, which is then drawn to align them. By aligned it is meant the axis along the longest dimension of each of the various particles in a local vicinity are substantially parallel.

Abstract: A method of manufacturing a GRIN lens includes a forming a wet gel from an alcohol solution containing a silicon alkoxide, a dopant alkoxide, and an aluminum alkoxide; dissolving by leaching the dopant and aluminum away from an outer peripheral surface of the wet gel to provide a refractive index distribution; forming a dry gel by drying the wet gel; forming a glass preform by firing the dry gel; and wire-drawing the perform. In the step of leaching, most aluminum dissolves from the wet gel, thereby increasing the porosity of the dry gel and preventing cracking during sintering and foaming during wire-drawing.

Abstract: The present invention relates to a preform for a glass ferrule and a fabrication method thereof. It is an objective of the present invention to fabricate dual hole ferrules having various distances between two holes by using a single preform. It is another objective of the present invention to fabricate a preform for a dual hole glass ferrule by a simple process. To meet the above and other objectives, the present invention provides a preform for a glass ferrule, comprising two holes which are formed through the preform and exit out both side cross-sections of the preform, wherein the two holes are symmetrical to the center in a diameter direction of the preform and a distance between the two holes changes in a lengthwise direction of the preform.

Abstract: A method for manufacturing an optical waveguide includes the steps of forming a liquid-repellent region upon a substrate, and forming the optical waveguide in a region upon the substrate other than the liquid-repellent region.

Abstract: Method for fabricating a glass-monolith by the sol-gel process, in which a pyrogenically produced silica (fumed silica) is used in the form of a powder and/or a dispersion, characterized in that as pyrogenically produced silica (fumed silica) a silica (fumed silica) deriving from the group highly pure, pyrogenically produced silica (fumed silica) with a metal content of lower than 9 ppm and/or a pyrogenically prepared silicon dioxide powder having—a BET surface area of 30 to 90 m2/g, —a DBP number of 80 or less, an average aggregate area of less than 25,000 nm2, an average aggregate circumference of less than 1,000 nm, at least 70% of the aggregates having a circumference of less than 1,300 nm is used.

Abstract: Internally colored glass and glass-like blocks (10) and the method for making them. No means for coating the internal cavities (26) of clear glass and glass-like hollow blocks has been available. Color coating provides aesthetically pleasing structures. Internally colored glass and glass-like blocks may be used in building internal room dividers, providing colorful building designs and for providing color relief in heretofore otherwise drab structures.

Abstract: An optical fibre having an axial direction and a cross section perpendicular to the axial direction, the optical fibre having a first light guiding fibre portion with a cladding region with a plurality of spaced apart cladding voids extending longitudinally in the fibre axial direction and a core region bounded by the cladding region, and a solid light transparent fibre portion having a first end facing the first light guiding fibre portion and a second end forming an end face of the optical fibre. The solid light transparent fibre portion provides a hermetic sealing of the cladding voids of the first light guiding fibre portion. A method of producing such an optical fibre and its use, such as an optical fibre connector and an article having a microstructured optical fibre with hermetically sealed end face, are also included.

Abstract: The present invention is directed to method of bonding mineral fibers in a mineral fiber material, according to which an acid is applied to the mineral fiber material in an amount sufficient to dissolve mineral material from the fiber to form a silica containing binder on the mineral fiber, and curing the mineral fiber material to bond the fibers.

Abstract: Silica sol techniques are described for making thick silica or silica based films useful for planar optical waveguides. The process involves coating of a colloidal silica sol onto a substrate, drying the sol, and consolidating the dried sol to form the planar waveguide. Coating is performed in a simple operation, either by dipping, or preferably by spin coating. In a preferred embodiment the substrate is coated with a wetting agent prior to spin coating. It is found that the wetting agent substantially improves the thickness uniformity of the layer. Thick waveguide layers may be produced by repeating the coating process one or more times to produce a layer with the desired thickness. Buried waveguides are produced by forming a doped core layer, patterning the doped core layer and using the coating technique of the invention to form the cladding material.

Abstract: A method of preparing a solution for forming a doped gel monolith includes providing a first substance including a metal alkoxide. The method further includes providing a second substance including a catalyst. The method further includes providing a chemical including a dopant. The method further includes forming a solution including the dopant, said forming including mixing the first substance and the second substance together. The method further includes cooling the solution to a mixture temperature which is at or below zero degrees Celsius, wherein the solution has a significantly longer gelation time at the mixture temperature than at room temperature.

Abstract: The use of large dense vitreous spherical (LDVS) silica powders for making sol-gel silica bodies has been found to have important advantages. Among these are higher gel strength, higher silica loading, more rapid aging and drying of the gel, a reduction in the amount of organic additives leading to reduced process time required for organic burn-off, and easier removal of contaminant particles due to their larger size. It was also discovered that combining LDVS particles with conventional non-spherical, lower density, aggregate particle mixtures, further improves the process.

Abstract: A simple, economic wet chemical procedure is described for making sol-gel fibers. The sol-gel fibers made from this process are transparent to ultraviolet, visible and near infrared light. Light can be guided in these fibers by using an organic polymer as a fiber cladding. Alternatively, air can be used as a low refractive index medium. The sol-gel fibers have a micro pore structure which allows molecules to diffuse into the fiber core from the surrounding environment. Chemical and biochemical reagents can be doped into the fiber core. The sol-gel fiber can be used as a transducer for constructing an optical fiber sensor. The optical fiber sensor having an active sol-gel fiber core is more sensitive than conventional evanescent wave absorption based optical fiber sensors.

Abstract: A method of forming a gel monolith includes preparing a first solution comprising metal alkoxide and preparing a second solution comprising a catalyst. A third solution is prepared by mixing the first solution and the second solution together. At least one of the first, second, and third solutions is cooled to achieve a mixture temperature for the third solution which is substantially below room temperature, wherein the third solution has a significantly longer gelation time at the mixture temperature as compared to a room temperature gelation time for the third solution. The method further includes allowing the third solution to gel, thereby forming the gel monolith.

Abstract: Sol-gel process for the production of optical fiber preforms or overcladdings by preparing a sol, gelling the sol, drying the wet gel to a dry porous gel and densifying the dry gel to fully dense glass, wherein during the calcination treatment from 350° C. to 900° C. to remove organic impurities in the dry gel, it is carried out at least one reduced-pressure phase at a pressure comprised between about 0.01 and 0.5 bar.

Abstract: A method for manufacturing an optical waveguide component with several layers stacked on a silicon substrate. The layers include a buffer layer, a first substrate, a guiding layer on the buffer layer and including an optical waveguide, and an outer layer as protection against external stresses. The layers are made from an organic-inorganic hybrid using a sol-gel process. An additional layer is disposed on the guiding layer so that a symmetrical structure is produced that has the same refractive index around the waveguide in the guiding layer.

Abstract: A mold is configured to form a gel monolith including a first gel portion and a second gel portion. The mold includes a base including a first hydrophobic surface. The mold further includes a tubular outer wall including a second hydrophobic surface, and the outer wall is coupled to the base. The mold further includes a removable tubular insert including an inner surface and an outer hydrophobic surface. The insert is removably coupled to the base.

Abstract: Techniques are described for fabricating a preform from a soot body. In one described technique, a soot body is loaded into a substrate tube, and the position of the soot body is stabilized within the tube. The tube is then rotated around its longitudinal axis. Heat is applied from a heat source to the substrate tube at a first end of the soot body to cause the first end of the soot body to begin to sinter and to cause the substrate tube to begin to at least partially collapse around the sintered portion of the soot body. The heat source is then advanced along the substrate tube and the soot body to cause a progressive sintering of the soot body, and to cause a progressive, at least partial, collapse of the substrate tube around the sintered portion of the soot body.

Abstract: A method forms an optical fiber preform. The method includes forming a sol-gel-derived rod having a first diameter. Forming the sol-gel-derived rod includes preparing a sol-gel solution including at least 3 mole % of a catalyst. The sol-gel solution is allowed to undergo gelation to form a wet gel monolith. The wet gel monolith is dried and shrunk by exposing the wet gel monolith to a temporal temperature profile, thereby forming a xerogel monolith. The xerogel monolith is consolidated, thereby forming the sol-gel-derived rod. The method further includes drawing the sol-gel-derived rod to substantially reduce its diameter, thereby forming a drawn rod having a second diameter less than the first diameter.

Abstract: Pyrogenically prepared silicon dioxide with the following physicochemical properties: 1. Average particle size (D50 value) D50?150 nm (dynamic light scattering, 30 wt %) 2. Viscosity (5 rpm, 30 wt %) ??100 m·Pas 3. Thixotropy of Ti (?(5 rpm))/(?(50 rpm))?2 4. BET surface area 30-60 m2/g 5. Compacted bulk=100-160 g/L 6. Original pH?4.5 that can be used for the preparation of dispersions and glass bodies.

Abstract: The present invention discloses a process for making rare earth (RE) doped optical fiber by using RE oxide coated silica nanoparticles as the precursor material, more particularly the method of the present invention involves preparation of stable dispersions (sol) of RE oxide coated silica nanoparticles at ambient temperature and applying a thin coating on the inner surface of silica glass tube following dip coating technique or any other conventional methods, of the said silica sol containing suitable dopants selected from Ge, Al, P, etc.

Abstract: A method of manufacturing a xerogel monolith having a pore diameter distribution includes preparing a first solution comprising metal alkoxide and preparing a second solution comprising a catalyst. A third solution is prepared by mixing the first solution and the second solution together. At least one of the first, second, and third solutions is cooled to achieve a mixture temperature for the third solution which is substantially below room temperature, wherein the third solution has a significantly longer gelation time at the mixture temperature as compared to a room temperature gelation time for the third solution. The method further includes allowing the third solution to gel, thereby forming a wet gel monolith. The method further includes forming the xerogel monolith by drying the wet gel monolith.

Abstract: The present invention discloses a method for fabricating silica glass using a sol-gel process, which includes a sol forming step for forming a sol by mixing a starting material, deionized water and an additive together; gelation step for gelatinizing the sol after filling a circular mold with the gel produced; gel drying step for separating the gel from the circular mold and drying the gel; setting step for placing the gel inside of a heat chamber and injecting helium gas into the heat chamber; and low heat treatment step for pressurizing and depressurizing an internal pressure of the heat chamber repeatedly for several times.

Abstract: The invention relates to inorganic hollow fibers, to a spinning mass and to a method for producing the same as well as to the use thereof for material transports, for the exchange of gases and in separation procedures. The hollow fibers according to the invention are obtainable by processing a spinning mass to a hollow fiber according to general methods, by curing said fiber thermally, via radiation induction or via chemical induction, and by removing the organic components via pyrolysis. The spinning mass is obtained by hydrolytic polycondensation of hydrolyzable compounds of silicon, aluminum, titanium and zirconium and optionally of co-condensable compounds of the elements Li, Na, Mg, Ca, Sr, Ba, Zn, Sn or Pb. The hydrolytic polycondensation is performed by adding water or moisture.

Abstract: The specification describes the production of optical fibers and optical fiber preforms using Chemical Powder Deposition (CPD). In this process a slurry of silica powders and dopant powders in a liquid carrier is prepared and the inside surface of a silica glass starter tube is coated with the slurry, then dried. The coating is then consolidated and the tube collapsed as in the conventional MCVD process. Multiple coatings, and coatings with varying compositions, can be used to produce any desired profile. In an alternative embodiment, doped silica glass of the desired final composition is prepared, and then pulverized to form the powder for the slurry. In both embodiments, the use of powders of known composition in the slurry allows direct control over the final glass composition, as compared with conventional processes in which the composition in the final glass is indirectly controlled by control of the thermodynamics of a vapor phase reaction.

Abstract: Silica sol techniques are described for making thick silica or silica based films useful for planar optical waveguides. The process involves coating of a colloidal silica sol onto a substrate, drying the sol, and consolidating the dried sol to form the planar waveguide. Coating is performed in a simple operation, either by dipping, or preferably by spin coating. In a preferred embodiment the substrate is coated with a wetting agent prior to spin coating. It is found that the wetting agent substantially improves the thickness uniformity of the layer.

Abstract: This invention discloses a method and an apparatus for sintering a gel tube formed by a sol-gel change. The sintering apparatus comprises a reaction chamber for accommodating the gel tube, sealed under a vacuum condition; a vacuum pump for adjusting the degree of vacuum inside the reaction chamber according to a control signal; a vacuum gauge for measuring the degree of vacuum inside the reaction chamber; a movable part for supporting the gel tube and for rotating and vertically moving the gel tube according to the control signal; a temperature sensor for measuring the temperature inside the reaction chamber; a heater for adjusting the temperature inside the reaction chamber according to the control signal so as to sinter the gel tube; and, a controller for controlling the vacuum pump, the heater, and the movable part for sintering the gel tube under the vacuum condition.

Abstract: A method of fabricating a halogen-doped glass includes providing a gel monolith having a first halogen content. The method further includes reducing an impurity concentration of the gel monolith. The method further includes consolidating the gel monolith into a glass having a second halogen content. The second halogen content is less than or equal to the first halogen content. A halogen-doped glass has a fluorine content in a range between approximately 0.5 wt. % and approximately 4 wt. %, a chlorine content less than 100 parts per million, and an OH content less than one part per million.

Abstract: A sol-gel process is described that allows dry gels to be produced, and where necessary, the corresponding dense vitreous bodies, around an incompressible insert. A particular feature of the process is the step of rotating a container holding the sol and incompressible insert throughout the gelling step under such conditions that a wet gel adhering to the insert is produced, which is then dried. The process is useful particularly for the production of preforms for optical fibers, which are also claimed.

Abstract: The present invention discloses a process for making rare earth (RE) doped optical fibre by using RE oxide coated silica nanoparticles as the precursor materia, more particularly the method of the present invention involves preparation of stable dispersions (sol) of RE oxide coated silica nanoparticles at ambient temperature and applying a thin coating on the inner surface of silica glass tube following dip coating technique or any other conventional methods, of the said silica sol containing suitable dopants selected from Ge, Al, P, etc.

Abstract: The use of large dense vitreous spherical (LDVS) silica powders for making sol-gel silica bodies has been found to have important advantages. Among these are higher gel strength, higher silica loading, more rapid aging and drying of the gel, a reduction in the amount of organic additives leading to reduced process time required for organic burn-off, and easier removal of contaminant particles due to their larger size. It was also discovered that combining LDVS particles with conventional non-spherical, lower density, aggregate particle mixtures, further improves the process.

Abstract: A photomask assembly is described having a frame for supporting a transparent pellicle above a photomask substrate, defining a closed pellicle space overlaying the substrate. The frame is formed of a porous material configured to allow the pellicle space to be purged with an inert gas within a reasonable processing time period, thereby removing any harmful chemicals that might be present. The frame preferably is made by a method that includes preparing a gel by a sol-gel process, drying the gel, and partially densifying the dry gel. The resulting frame has a gas permeability to oxygen or nitrogen higher than about 10 ml.mm/cm2.min.MPa, an average pore size between 0.001 micrometer and 10 micrometers, and a coefficient of thermal expansion between 0.01 ppm/° C. and 10 ppm/° C.

Abstract: Disclosed are silica structure crack detection methods and apparatuses particularly useful in sol-gel fabrication processes. A wave signature of a crack in the silica structure is sensed to indicate that cracking has occurred. Sensing may be by active or passive techniques and may include contact and non-contact methods of monitoring. Further disclosed is a silica structure fabrication process development method wherein cracks are monitored by sensing a wave signature of a crack to isolate a process step or steps in which cracking has occurred. Process parameters are then adjusted in the isolated step to diminish or eliminate cracking.

Abstract: A process produces a glass overcladding tube from a silica gel body. The process includes passing the gel body through a hot zone under conditions that cause partial sintering of the gel body and repassing the gel body through the hot zone under conditions that further sinter the gel body into a glass overcladding tube.

Abstract: A method of manufacturing a magnetic recording medium including a servo pattern, comprising steps of: (a) providing a non-magnetic substrate including at least one major surface; (b) providing a stamper having a surface with a plurality of recesses forming a negative image of a servo pattern; (c) forming a layer of a partially dried sol-gel material having a first surface in conformal contact with the recess-patterned surface of the stamper and an exposed second surface opposite the first surface; (d) urging the major surface of the substrate into contact with the exposed second surface of the sol-gel layer; (e) removing the stamper from contact with the layer of sol-gel material to expose the recess-patterned surface thereof; (f) converting the partially dried sol-gel layer to a glass-like layer while preserving the recess pattern in the surface thereof; and (f) forming on the recess-patterned surface a laminate of layers constituting a servo-patterned magnetic recording medium.

Abstract: A first waveguide and a second waveguide are aligned by applying an alignment dot on end surfaces of the cores of first and second waveguides. The alignment dots are positioned in close proximity to one another, and are melted together. Surface tension pulls the first and second waveguides into alignment.

Abstract: The present invention provides methods for fabricating optical fiber preforms and optical fibers. According to one embodiment of the invention, a method for making an optical fiber preform includes the steps of providing at least one sacrificial rod having an outside surface; forming a material on the outside surface of each sacrificial rod to yield a structured body, the structured body including a structured material in substantial contact with the at least one sacrificial rod; removing each sacrificial rod from the structured body; and including the structured body in the optical fiber preform. The preform may be drawn into an optical fiber. The methods of the present invention are especially useful in the fabrication of microstructured optical fibers.