Yazaki Corporation

Nextrom Oy

Ensign-Bickford Optical Technologies, Inc.

Orion Laboratories, LLC

Cal-Optics, Inc.

Spectran Communications Fiber Technologies, Inc.

Arnab Sarkar

Satyabrata Raychaudhuri

Shiho Wang

Fikret Nuri Kirkbir

Yongan Yan

Edward J Pope

Bedros Orchanian

Shi-Ho Wang

Din-Guo Chen

Yoshitake Sato

Yoji Sano

An outside chemical vapor deposition apparatus is disclosed for depositing porous glass-forming material onto a target rod to form a cylindrical body, with substantially higher efficiency than could prior apparatus. The apparatus includes two separate burner arrays, one array optimized for depositing the material during an initial stage of the process, when the cylindrical body has a relatively small diameter, and the other array optimized for depositing the material during a later stage of the process, when the cylindrical body has a relatively large diameter. In addition, each burner array can include a plurality of burners, with each burner azimuthally angled relative to the apparatus' air-flow axis, and with adjacent burners angled in opposite directions relative to that axis, to minimize the density gradient within the deposited porous material.

Apparatus for deposition by flame hydrolysis

A sol-gel process is disclosed for depositing multi-layer antireflection coatings on plastic substrates. One or more polymerized, titanium-containing solutions are provided by mixing a titanium alkoxide, an alcohol, and water, and one or more polymerized, silicon-containing solutions are provided by mixing a silicon alkoxide, an alcohol, and water. These solutions are applied to the plastic substrate in an alternating fashion, to produce a succession of uniform layers of polymerized titanium dioxide and polymerized silicon dioxide. Each layer is individually cured before the next layer is applied. The resulting coating of multiple polymerized layers provides very low reflectance over the entire visible wavelength range, yet with excellent mechanical strength and durability.

Plastic articles having multi-layer antireflection coatings, and sol-gel

Low attenuation, low dispersion of optical waveguides are provided by a process initiating with axial deposition of a high velocity core soot stream impinging on, a target at a high angle of incidence relative to the axis of rotation of the target. A core cylinder is built up axially by relative movement between the soot stream and target during deposition, the movement being non-constant in order to maintain a substantially constant diameter with a constant deposition rate. A cladding layer is then built up by deposition of soot radially on the core. Subsequent drying and sintering provides a vitreous preform which may be drawn directly into optical waveguides. Alternatively, the sintered product may be drawn down to smaller rods, which then are covered with further deposited soot cladding to a desired final thickness, and after further drying and sintering may be drawn to optical waveguides.

Methods of making optical waveguides

Low attenuation, low dispersion of optical waveguides are provided by a process initiating with axial deposition of a high velocity-core soot stream impinging on a target at a high angle of incidence relative to the axis of rotation of the target. A core cylinder is built up axially by relative movement between the soot stream and target during deposition, the movement being non-constant in order to maintain a substantially constant diameter with a constant deposition rate. A cladding layer is then built up by deposition of soot radially on the core. Subsequent drying and sintering provides a vitreous preform which may be drawn directly into optical waveguides. Alternatively, the sintered product may be drawn down to smaller rods, which then are covered with further deposited soot cladding to a desired final thickness, and after further drying and sintering may be drawn to optical waveguides.

A process and apparatus are described for rapidly drying a wet, porous gel monolith of glass or ceramic, at subcritical temperatures without inducing any cracking of the gel. The wet gel is immersed in a liquid solvent in a chamber, and the liquid solvent is then heated and expelled from the chamber. Further heating, with or without the presence of a flowing inert gas, fully dries the wet gel. When an inert gas is used, the gas is delivered to the chamber with a controlled solvent partial vapor pressure, to correspondingly control the driving force for drying the gel.

Apparatus for rapidly drying a wet, porous gel monolith

An improved sol-gel process for fabricating large, crack-free gel monoliths (e.g., of silica) is described in which a specially-tailored gel microstructure is provided by adjusting the relative concentrations of an alcohol diluent (e.g., ethanol) and/or one or more catalysts (e.g., HCl and HF). Controlled variations in the gel's average pore radius, bulk density, rupture modulus, and elastic modulus over a wide range can be tailored in this fashion. This enables the process to be optimized for the particular application involved.

Sol-gel process for providing a tailored gel microstructure

A process and apparatus are described for rapidly drying a wet, porous gel monolith of glass or ceramic, at subcritical temperatures without inducing any cracking of the gel. The wet gel in immersed in a liquid solvent in a chamber, and the liquid solvent is then heated and expelled from the chamber. Further heating, with or without the presence of a flowing inert gas, fully dries the wet gel. When an inert gas is used, the gas is delivered to the chamber with a controlled solvent partial vapor pressure, to correspondingly control the driving force for drying the gel.

Process for rapidly drying a wet, porous gel monolith

Low attenuation, low dispersion of optical waveguides are provided by a process initiating with axial deposition of a high velocity core soot stream impinging on a target at a high angle of incidence relative to the axis of rotation of the target. A core cylinder is built up axially by relative movement between the soot stream and target during deposition, the movement being non-constant in order to maintain a substantially constant diameter with a constant deposition rate. A cladding layer is then built up by deposition of soot radially on the core. Subsequent drying and sintering provides a vitreous preform which may be drawn directly into optical waveguides. Alternatively, the sintered product may be drawn down to smaller rods, which then are covered with further deposited soot cladding to a desired final thickness, and after further drying and sintering may be drawn to optical waveguides.

An improved sol-gel process is disclosed for fabricating large monoliths of silica or ceramic material, which are substantially free of cracks. Following formation of the gel, but before the gel is dried, the gel is subjected to a hydrothermal aging treatment, in which it is heated in an autoclave to a temperature of between 100.degree. and 300.degree. C., for a time duration of at least about one hour. This hydrothermal aging treatment causes silica (or ceramic) particles to migrate and fill small pores in the porous gel matrix, such that the average pore size increases and capillary forces encountered in the subsequent drying step are reduced to a point where cracking of the gel is substantially eliminated.

Growing community of inventors

West Hills, CA, United States of America

Arnab Sarkar