Glasses having low OH, OD levels
AssigneeCorning Incorporated
InventorsDana Craig Bookbinder, Richard Michael Fiacco, Kenneth Edward Hrdina, Rostislav Radievich Khrapko
Life of this patent
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Abstract
A fused silica glass and a fused silica article having a combined concentration of at least one of OH and OD of up to about 50 ppm. The fused silica glass is formed by drying a fused silica soot blank or preform in an inert atmosphere containing a drying agent, followed by removal of residual drying agent from the dried soot blank by heating the dried soot blank in an atmosphere comprising an inert gas and of oxygen.
Claims19
A fused silica article, the fused silica article comprising OD and, optionally, OH, wherein OH and OD are present in a combined concentration of up to about 50 ppm, wherein the ratio of OD concentration to the sum of OD concentration and OH concentration is greater than the natural isotopic abundance of deuterium, wherein the fused silica article is free of straie, and wherein the fused silica article has a refractive index variation at a wavelength of 633 nm of less than about 5 ppm:
- i. in a direction in which the OH concentration and OD concentration have a combined variation of less than 25 ppm;
- and
- ii. over a distance of at least about 50 mm along a dimension of the sample perpendicular to incident light.
A method of making a fused silica glass, the fused silica glass comprising OD and, optionally, OH, wherein OH and OD are present in a combined concentration of up to about 50 ppm, wherein the fused silica article is free of straie, and wherein the ratio of OD concentration to the sum of OD concentration and OH concentration is greater than the natural isotopic abundance of deuterium, the method comprising the steps of:
- a. providing a silica soot blank, the soot blank comprising OD and, optionally, OH;
- b. drying the soot blank to form a dried soot blank in an atmosphere comprising an inert gas and a predetermined concentration of at least one drying agent at a predetermined temperature, wherein the drying agent removes OH and OD from the soot blank;
- c. removing the at least one drying agent from the dried soot blank;
- and
- d. sintering the soot blank to form the fused silica glass comprising OD and, optionally, OH, wherein OH and OD are present in a combined concentration of up to about 50 ppm.
An article comprising fused silica glass, the fused silica comprising OD and, optionally, OH, wherein OH and OD are present in a combined concentration of up to about 50 ppm, wherein the ratio of OD concentration to the sum of OD concentration and OH concentration is greater than the natural isotopic abundance of deuterium, wherein the fused silica article is free of straie, and wherein the fused silica glass has a refractive index variation at a wavelength of 633 nm of less than about 5 ppm:
- i. in a direction in which the OH concentration and OD concentration have a combined variation of less than 25 ppm;
- and
- ii. over a distance of at least about 50 mm along a dimension of the sample perpendicular to incident light, wherein the fused silica article is formed by:
- a. providing a silica soot blank, the soot blank comprising OD and, optionally, OH;
- b. drying the soot blank to form a dried soot blank in an atmosphere comprising an inert gas and a predetermined concentration of at least one drying agent at a predetermined temperature, wherein the drying agent removes OH and OD from the soot blank;
- c. removing the at least one drying agent from the dried soot blank;
- and
- d. sintering the soot blank to form the fused silica glass.
Dependencies are inferred from the claim text.