A method for producing rare earth metal-doped quartz glass includes the steps of (a) providing a blank of the rare earth metal-doped quartz glass, and (b) homogenizing the blank by softening the blank zone by zone in a heating zone and by twisting the softened zone along a rotation axis. Some rare earth metals, however, show a discoloration of the quartz glass, which hints at an unforeseeable and undesired change in the chemical composition or possibly at an inhomogeneous distribution of the dopants. To avoid this drawback and to provide a modified method which ensures the production of rare earth metal-doped quartz glass with reproducible properties, during homogenization according to method step (b), the blank is softened under the action of an oxidizingly acting or a neutral plasma.

Computer-implemented methods and apparatus are provided for predicting/estimating (i) a non-equilibrium viscosity for at least one given time point in a given temperature profile for a given glass composition, (ii) at least one temperature profile that will provide a given non-equilibrium viscosity for a given glass composition, or (iii) at least one glass composition that will provide a given non-equilibrium viscosity for a given time point in a given temperature profile. The methods and apparatus can be used to predict/estimate stress relaxation in a glass article during forming as well as compaction, stress relaxation, and/or thermal sag or thermal creep of a glass article when the article is subjected to one or more post-forming thermal treatments.

A glass container has a container main body made of glass and a coating film formed on a surface of the container main body. The coating film is made of tin oxide or titanium oxide, and the film thickness of the coating film ranges from 40 nm to 50 nm. In the depth profile obtained by X-ray photoelectron spectroscopy (XPS) analysis, an atomic percentage of sodium at a point where a tin or titanium profile intersects a silicon profile is 2% or less.

A glass container has a container main body made of glass and a coating film formed on a surface of the container main body. The coating film is made of tin oxide or titanium oxide, and the film thickness of the coating film ranges from 40 nm to 50 nm. In the depth profile obtained by X-ray photoelectron spectroscopy (XPS) analysis, an atomic percentage of sodium at a point where a tin or titanium profile intersects a silicon profile is 2% or less.

A method of manufacturing a polarizing glass sheet includes subjecting, while heating, a glass preform sheet containing metal halide particles to down-drawing, to thereby provide a glass member having stretched metal halide particles dispersed in an aligned manner in a glass matrix, and subjecting the glass member to reduction treatment to reduce the stretched metal halide particles, to thereby provide a polarizing glass sheet. A shape of the glass preform sheet during the down-drawing satisfies a relationship of the following expression:

L.sub.1/W.sub.11.0

where L.sub.1 represents a length between a portion in which a width of the glass preform sheet has changed to 0.8 times an original width and a portion in which the width of the glass preform sheet has changed to 0.2 times the original width W.sub.0, and W.sub.1 represents a length equivalent to 0.5 times the original width W.sub.0 of the glass preform sheet.

Provided is a method for manufacturing an infrared-transmissive lens having an excellent surface quality. A method for manufacturing an infrared-transmissive lens includes firing a preform of a chalcogenide glass in an inert gas atmosphere to obtain a fired body and then subjecting the fired body to hot press molding.

The invention discloses a method and an apparatus for drying and cooling a glass substrate. The method comprises the steps described below. The method delivers the glass substrate cleaned by a cleaner into a baking oven by a first roller device. It dries the glass substrate using an infrared heating plate installed in the baking oven. It delivers the dried glass substrate into a cooling chamber by a second roller device. It cools the dried glass substrate using a cooling plate installed in the cooling chamber. And it delivers the cooled glass substrate onto a platform of an air floating type coater, and coating the glass substrate. This invention also discloses an apparatus corresponding to the method. According to the embodiments of the present invention, it is possible to reduce the number of foreign particles on the glass substrate before coating, and the drying effect is excellent.

The invention discloses a method and an apparatus for drying and cooling a glass substrate. The method comprises the steps described below. The method delivers the glass substrate cleaned by a cleaner into a baking oven by a first roller device. It dries the glass substrate using an infrared heating plate installed in the baking oven. It delivers the dried glass substrate into a cooling chamber by a second roller device. It cools the dried glass substrate using a cooling plate installed in the cooling chamber. And it delivers the cooled glass substrate onto a platform of an air floating type coater, and coating the glass substrate. This invention also discloses an apparatus corresponding to the method. According to the embodiments of the present invention, it is possible to reduce the number of foreign particles on the glass substrate before coating, and the drying effect is excellent.

A device for manufacturing SiO.sub.2TiO.sub.2 based glass by growing a glass ingot upon a target by a direct method. The device includes the target, comprising a thermal storage portion that accumulates heat by being preheated, and a heat insulating portion that suppresses conduction of heat from the thermal storage portion in a direction opposite to the glass ingot.

Provided is a silica glass member which exhibits high optical transparency to vacuum ultraviolet light and has a low thermal expansion coefficient of 4.010.sup.7/K or less at near room temperature, particularly a silica glass member which is suitable as a photomask substrate to be used in a double patterning exposure process using an ArF excimer laser (193 nm) as a light source. The silica glass member is used in a photolithography process using a vacuum ultraviolet light source, in which the fluorine concentration is 1 wt % or more and 5 wt % or less, and the thermal expansion coefficient at from 20 C. to 50 C. is 4.010.sup.7/K or less.