Hoya Corporation

Other

Raychem Limited

Hoya Optics, Inc.

Hisayoshi Toratani

Xuelu Zou

Hiroaki Yanagita

Helmuth E Meissner

Katsuhisa Itoh

Sadahiro Nakajima

Koji Sato

Tetsuro Izumitani

Hiromasa Tawarayama

Huai-Chuan Lee

Takeshi Takahashi

Takeshi Yao

Tomoko Kasuga

Yeong Lin

Hiroshi Kato

Chiemi Kanamori

Tajima Hidemi

Etsuko Hayashi

A light polarizing glass article comprising a base glass and metallic copper particles dispersed in said base glass wherein said metallic copper particles have aspect ratios in the range of from about 2:1 to 15:1 and said base glass is selected from the group consisting of silicate, borosilicate, borate and phosphate glasses which contain at least one reductant element. The article is prepared by heating a batch of glass containing copper and halogen containing constituents to develop copper halide particles in the glass, elongating said glass containing copper halide particles at a temperature where said glass exhibits a viscosity of from 1&times;10,to 1&times;10,poises, and reducing at least a portion of the copper halide particles in the elongated glass to produce metallic copper particles therein. An optical isolator employing the above light polarizing glass articles is also provided.

Light polarizing glass containing copper particles and process for preparation thereof

Disclosed is disc substrate consisting of SiO,&mdash;Al,O,&mdash;RO (RO&equals;divalent metal) glasses having high specific elastic modulus of 36&times;10,Nm/kg or more or high Young's modulus of 110 GPa or more, high transition temperature of 700&deg; C. or higher (high heat resistance), excellent surface smoothness (surface roughness Ra<5 &angst;) and high strength. The substrates exhibiting high specific elastic modulus or high Young's modulus and high strength enables to realize thinner magnetic discs and prevent breakdown of magnetic discs. Since glass substrates being composed of the glass have excellent heat resistance and flatness, the substrates can be subjected to heat treatment for improvement of magnetic layer characteristics and realize smaller flying height of magnetic head, i.e., higher recording density.

Disc substrates for information recording discs and magnetic discs

Glass substrate for magnetic recording medium and method of manufacturing the same

Process for producing titanium oxide thin film, and photocatalyst

A material according to the invention is made of a glass whose transition temperature is 750 degrees Celsius or greater and used for a substrate for information recording media, and for example, the glass has an essential component made of any group chosen from SiO.sub.2 --Al.sub.2 O.sub.3 --MgO--CaO, SiO.sub.2 --Al.sub.2 O.sub.3 --MgO--Y.sub.2 O.sub.3, SiO.sub.2 --Al.sub.2 O.sub.3 --CaO--Y.sub.2 O.sub.3, SiO.sub.2 --Al.sub.2 O.sub.3 --MgO--CaO--Y.sub.2 O.sub.3, and SiO.sub.2 --Al.sub.2 O.sub.3 --M.sub.2 O.sub.3 (wherein M denotes a trivalent metal.). This material can form a substrate for information recording media, or more specifically, a substrate on which at least a magnetic layer is formed to constitute a magnetic disc. A manufacturing method for magnetic disc according to the invention includes a process to improve a coercive force of a magnetic layer by thermally treating the magnetic layer at a temperature at least 40 degrees Celsius below the transition temperature of the material forming the substrate for the magnetic disc, where at least the magnetic layer is formed on the substrate made of the above material. The material is suitable for a substrate for information recording media made of the glass having an excellent surface flatness and mechanical strength and property durable against a heat treatment implemented at a high temperature for improving magnetic characteristics of the magnetic layer. This material is applicable to a substrate, a magnetic recording media in use of the substrate, and a manufacturing method for such information recording media.

Substrate for information recording media and magnetic disc

A method for seeking, from an outer circle radius a, an inner circle radius b, and a thickness h of a disc substrate and a deflection Wmax permissive at a time of rotation, a specific elastic modulus G that a material forming the substrate has, ##EQU1## The material for providing a substrate for information recording media having a thickness h of 0.6 millimeter and a deflection Wmax of 1.4 micrometer has a specific elastic modulus G satisfying above Formula (1).

Method for selecting a material suitable for a substrate for information

Disclosed are an optical fiber comprising a core and a cladding wherein the core is composed of a In-Ga-Cd-Pb halide glass and the clad composed of a halide glass possesses a refractive index of 1.515 or less, which has a large specific refractive index difference (.DELTA.n) and a large numerical aperture, and such an optical fiber as mentioned above wherein the core contains one or more activating ions as well as an optical fiber amplifier comprising a pumping source, a laser glass fiber and a means for introducing pumping light and signal light into the above laser glass fiber, wherein the laser glass fiber is the optical fiber of the present invention mentioned above.

Optical fibers and optical fiber amplifiers

Disclosed are laser glasses composed of a Ga--Na--S glasses doped with one or more kinds of activating ions, laser glass fibers comprising a core and a clad wherein the core is composed of the above-mentioned laser glasses of the present invention and optical fiber amplifiers comprising a pumping source, a laser glass fiber and a means for introducing pumping light and signal light into the laser glass fiber wherein the laser glass fiber is the above-mentioned laser glass fiber of the present invention. The laser glasses of the present invention show high radiative quantum efficiency and host glass stability and can be produced easily.

Laser glasses and laser glass fibers

Faraday rotation glass having a practically sufficiently large Verdet's constant, which contains 60 to 75 mol % of P.sub.2 O.sub.5, 10 to 20 mol % of Tb.sub.2 O.sub.3 and 10 to 25 mol % of K.sub.2 O and having substantially no platinum inclusion.

Faraday rotation glass

A phosphate based laser glass composition for high average power systems including by mol percent 60-66% P.sub.2 O.sub.5, 6-9% Al.sub.2 O.sub.3, 8-12% Li.sub.2 O, 0-15% MgO, 0-15% ZnO, 0-5% B.sub.2 O.sub.3 and 0.1-4%, Nd.sub.2 O.sub.3, with MgO+ZnO totaling 14-16%.

Glass of improved thermal shock resistance for high average power solid

Processes in which glass parts are strengthened by ion exchange with cations in a molten salt bath are improved by removal of the small amounts of moisture and other forms of the hydroxyl group present in the salt melt by either chemical or electrolytic means, prior to the ion exchange. The chemical means involve reacting the hydroxyl-containing compounds with the chlorine-containing gas, while the electrolytic means involve electrolysis to gaseous hydrogen and oxygen. Preferred embodiments further include a gas purge prior to the chemical or electrolytic treatment.

Avoidance of surface deterioration of glass during strengthening

An antireflective coating and a process for producing the same are described. This antireflective coating has the difference in refractive index between the glass interface and the outer surface of the antireflected coating of 0.15 or less. This antireflective coating can be formed by treating a glass with an aqueous solution containing specified amounts of an acidic salt, Al.sup.3+ and Si.sup.4+. The antireflective coating has a high mechanical strength and optical elements having such an antireflective coating are useful for use in the laser nuclear fusion system.

Process for producing porous antireflective coatings

A method of increasing the thermal shock resistance of a phosphate laser glass is described, comprising coating the surface of the glass with a sol solution which is prepared by hydrolyzing at least one organometallic compound dissolved in an organic solvent and then partially polycondensing, and then heat-treating to form a glassy coating on the surface of the glass. The phosphate laser glass having such increased thermal shock resistance is useful for high repetitive operation.

Method of increasing the thermal shock resistance of phosphate laser

A glass for edge-cladding a disc laser glass, comprising, in mol%, followed in parentheses by wt % value,

Edge-cladding glass of disc laser glass

A phosphate optical glass, whose length of the light path is substantially independent of temperature, comprising, in % by weight,

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Tokyo, Japan

Hisayoshi Toratani