Abstract: The present invention relates to a black quartz glass comprising Si of 0.5 to 10 mass %, SiO of 0.1 to 5 mass % and SiO2 of the residue, wherein the SCE reflectance at a wavelength of 350 nm to 750 nm is 10% or less; a method for producing the black quartz glass, comprising: pressure-molding a powder obtained by mixing and consolidating (1) fumed silica, or (2) a mixture powder of fumed silica and a synthetic silica powder, or (3) a mixture powder of fumed silica, spherical silica and a synthetic silica powder, with a Si powder of 0.5 to 10 mass % and a SiO powder of 0.1 to 5 mass %, and heating and sintering the pressure-molded product in the atmosphere; and a product comprising a black quartz glass member made of the black quartz glass.

Abstract: The present invention relates to a black quartz glass consisting of a composition comprising 63 to 65 mass % of SiO2, 18 to 24 mass % of TiO2, and 12 to 17 mass % of Al2O3, wherein the sum of SiO2, TiO2 and Al2O3 is 100 mass %; and to a method for producing black quartz glass comprising: mixing 63 to 65 mass % of a SiO2 powder, 18 to 24 mass % of a TiO2 powder and 12 to 17 mass % of an Al2O3 powder, filling the mixed powder into a mold and then melting at a maximum temperature of 1700 to 1900° C. in an oxygen-free atmosphere, and cooling to room temperature to obtain the black quartz glass; and further to a product comprising a black quartz glass member made of the black quartz glass.

Abstract: The present invention pertains to: a method for manufacturing an ultraviolet-resistant quartz glass, said method including melting a synthetic silica powder; and a method for manufacturing an ultraviolet-resistant quartz glass, said method including performing arc plasma melting of a silica powder. Provided is an ultraviolet-resistant quartz glass having an ultraviolet-resistance of 2500 seconds, wherein, taking the initial transmittance during irradiation of a quadruple higher harmonic (266 nm) of a YAG laser (irradiation performed at a YAG laser output of 180 mW, pulse width of 20 nsec, and frequency of 80 kHz) at an optical path length of 30 mm to be 100%, the irradiation period until the transmittance falls to 3% is defined as resistance to ultraviolet rays (referred to as ultraviolet-resistance). Also provided is an optical member for YAG-laser higher harmonics, said optical member comprising this quartz glass.

Abstract: Fused silica glass having an internal transmittance of UV with 245 nm wavelength, being at least 95% at 10 mm thickness, a OH content of not larger than 5 ppm, and a content of Li, Na, K, Mg, Ca and Cu each being smaller than 0.1 ppm. Preferably the glass has a viscosity coefficient at 1215° C. of at least 1011.5 Pa·s; and a Cu ion diffusion coefficient of not larger than 1×10?10 cm2/sec in a depth range of greater than 20 ?m up to 100 ?m, from the surface, when leaving to stand at 1050° C. in air for 24 hours. The glass is made by cristobalitizing powdery silica raw material; then, fusing the cristobalitized silica material in a non-reducing atmosphere. The glass exhibits a high transmittance of ultraviolet, visible and infrared rays, has high purity and heat resistance, and exhibits a reduced diffusion rate of metal impurities, therefore, it is suitable for various optical goods, semiconductor-production apparatus members, and liquid crystal display production apparatus members.

Abstract: Highly durable silica glass comprising silica having incorporated therein aluminum and at least one element (M) selected from group 2A elements, group 3A elements and group 4A elements of the periodic table. Preferably, the sum of aluminum and element (M) is at least 30 atomic % based on the amount of total metal elements in the silica glass, and the atomic ratio of aluminum to element (M) is in the range of 0.05 to 20. The silica glass has a high purity and exhibits enhanced durability while good processability and machinability, and reduced dusting property are kept, and the glass is suitable for members of a semiconductor production apparatus or liquid crystal display production apparatus using a halogenated gas and/or its plasma.

Abstract: Highly durable silica glass containing 0.01% to 2% by weight of at least one element selected from magnesium, calcium, strontium, barium, yttrium, hafnium and zirconium. The silica glass is produced by melting a powdery material comprising a finely divided silica powder and a finely divided zirconium-containing substance by oxyhydrogen flame or plasma are to form an accumulated molten material layer, and extending the molten material layer outwardly in radial directions.