Abstract: With the defect repairing of the present invention, gallium ions are irradiated/injected at a specified position for a glass substrate corresponding to a defect remaining after digging of a trench into a Levenson mask using a focused ion beam apparatus, the glass substrate into which the gallium ions have been injected then being soaked in an alkaline solution so that portions impregnated with gallium ions are removed by dissolving in a localized manner.

Abstract: The object of the invention is a method and a device for making visually distinguishable markings on the lower surface of a transparent material (5), using a vehicle (1). The marking is provided by causing a mixing of the transparent material and the vehicle by using a laser beam directed through the transparent material. The method can also be used to make markings on laminated glass without damaging the laminate.

Abstract: The invention relates to a lithium-sodium-aluminosilicate glass composition. This glass composition has a softening point of 700° C. or lower; a first temperature (1450° C. or lower) at which the glass composition exhibits a viscosity of 102 poises; a second temperature (1000° C. or lower) at which the glass exhibits a viscosity of 104 poises; and a mean thermal expansion coefficient between 30° C. and a glass transition temperature of the glass composition. This coefficient is within a range of from 90×10−7/° C. to 130×10−7/° C. The glass composition can be easily formed into a precursor of a glass article by pressing. It is possible to obtain a glass article that is chemically strengthened from the precursor by conducing alkali ion exchange.

Abstract: A simple and economical method is described for compacting or shrinking flat glass panes. The method ensures high temperature homogeneity in the glass. First, the glass panes are cleaned and then a stack of glass panes to be treated is assembled without applying a release agent to any of the glass panes. Then the stack of glass panes is placed between ceramic panels made of silicon-infiltrated silicon carbide and this stack together with the ceramic panels is subjected to a heat treatment in a radiation furnace at temperatures ranging from 300° C. to 900° C. The ceramic panels have a thermal conductivity, which, in the region of the heat treatment temperature, is at least 5 times as large as that of the glass panes. The ratio of the total thickness of the ceramic panels to the height of the glass stack should be at least 1/&lgr;/40W/(mK), wherein &lgr; is the thermal conductivity of the ceramic panel at the temperatures of the heat treatment.

Abstract: An object of the present invention is to prevent the adhesion of particles such as fine iron powders onto a glass substrate upon the production of a glass substrate for an information recording medium.

Abstract: Method is disclosed for making glass having both polarizing and non-polarizing regions integral thereto by either ion-exchange or by exposure to light and heat. The polarizing regions of the resulting glass is effective in polarizing light radiation, that is, the glass exhibits permanent dichroic behavior and has at least some polarizing effect in the wavelength range of 400 to 700 nm. The base glass composition contains Cu, Ag and at least one halide such that the resulting precipitated crystal phase consists of a halide.

Abstract: A quartz glass which would not become a source for the contamination even if it contains metallic impurities. This quartz glass includes a region where a concentration of E′ center as measured by means of an electron spin resonance analysis is 3×1019 cm−3 or more. This quartz glass can be manufactured by a method including the steps of forming an initial quartz glass by melting and quenching a raw material for quartz glass, and implanting therein an ion, which is capable of entering into an SiO2 network of the initial quartz glass and substantially incapable of externally diffusing, to increase a concentration of E′ center in at least part of the initial quartz glass. This quartz glass can be manufactured by a method making use of a quartz glass raw material containing 0.01 to 0.1% by weight of silicon, by a method of irradiating ultraviolet ray to the initial quartz glass, or by a method of giving an abrasion damage to the surface of the initial quartz glass by means of sand blast.

Abstract: A sheet of silicate glass having a thickness of 2 mm and composed mainly of SiO2, and containing Al2O3, B2O3, Na2O, F, etc., is immersed in a molten salt comprising a mixture of 50 mol % of silver nitrate and 50 mol % of sodium nitrate. Na ions in the surface of the glass are eluted, diffusing Ag ions in the molten salt into the glass. When a laser beam is applied to the glass substrate thus formed, the glass substrate is evaporated or ablated progressively from its surface. The glass substrate is processed to a smooth finish without causing cracking or breakage.

Abstract: A laser processing method for removing glass by melting, evaporation or ablation from sheet-like glass substrate for forming microscopic concavities and convexities. Diffraction grating and planar microlens array obtained thereby.

Abstract: A non-phase separable glass material for fabricating a GRIN lens comprises 5-20 mole % boron oxide and ratio R of network modifiers in mole % to the network former boron oxide in mole % is in the range of about 1-1.5. The melted preform of such glass material is extruded through an opening to form a glass rod where the extrusion process eliminates bubbles that may be present in the preform. Neodymium oxide may be added in the frit material for forming the preform to reduce friction forces in the extrusion process and reduces the stress in the glass rod. Centerless grinding may be performed to control the diameter and roughness of the surface of the rod to control the diffusion parameters during the subsequent ion-exchange.