Abstract: The invention relates to a process for making a SiO2—RExOy—Al2O3 glass comprising preparing a glass according to a conventional process wherein the conventional process comprises a step of heat treating a mixture of SiO2, RExOy, and Al2O3 at a temperature greater than the spinodal temperature for 0.1 to 10 hours wherein RExOy is a rare earth oxide and RE is a rare earth element chosen from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and combinations thereof. The invention also relates to glasses prepared by the process and glass lasers, optical amplifiers and laminated glass that comprise the glass prepared by the process.

Abstract: The invention relates to a process for making a SiO2—RExOy—Al2O3 glass comprising preparing a glass according to a conventional process wherein the conventional process comprises a step of heat treating a mixture of SiO2, RExOy, and Al2O3 at a temperature greater than the spinodal temperature for 0.1 to 10 hours wherein RExOy is a rare earth oxide and RE is a rare earth element chosen from Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and combinations thereof. The invention also relates to glasses prepared by the process and glass lasers, optical amplifiers and laminated glass that comprise the glass prepared by the process.

Abstract: A process for the preparation of crystalline silica powder from amorphous silica powder is disclosed. The water and hydroxyl content in the crystalline powder is much lower than that in the amorphous silica powder. The process involves heating the amorphous silica powder in the presence of a noble metal without the need for adding an impurity, such as an alkali crystallization promoter. Preferably, the amorphous silica powder is sol-gel derived, and a high purity silica glass product can therefore be made having a water content of less than 0.1 ppm.

Abstract: A radiation coloration resistant glass is disclosed which is used in a radiation environment sufficient to cause coloration in most forms of glass. The coloration resistant glass includes higher proportions by weight of water and has been found to be extremely resistant to color change when exposed to such radiation levels. The coloration resistant glass is free of cerium oxide and has more than about 0.5% by weight water content. Even when exposed to gamma radiation of more than 10.sup.7 rad, the coloration resistant glass does not lose transparency.