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AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsIshwar D. Aggarwal, Celia I. Merzbacher, Barry B. Harbison, John M. Jewell
Estimating the term…
A preferred embodiment of a sulfide glass with improved mechanical and optical properties such as extended transmission in the infrared region of radiation having wavelengths of up to about 15 microns, Tg in the range of 370.degree.-550.degree. C., and thermal stability of 100.degree.-300.degree. C., containing, on mol basis, 36-72% germanium sulfide, 2-38% gallium sulfide and/or indium sulfide, and 26-62% of at least one modifier containing an alkaline earth sulfide. A process for making glass of improved mechanical and optical properties comprises the steps of mixing glass components, including an alkaline earth modifier in elemental or sulfide form; melting the glass components in an inert vessel contained in a sealed ampoule to form a molten mixture; cooling the molten glass mixture to a solid state; annealing the solid glass; and cooling the annealed glass to about room temperature. The glass components can be in elemental form or in sulfide form, and if in elemental form, then sufficient amount of sulfur is added to form sulfides of the glass components.
A glass substantially free of crystallites defined by a polygon having x, y, and z coordinates for points l, m, n, o and p on a ternary graph wherein 100% germanium sulfide is at the apex x, 100% gallium sulfide/indium sulfide is at the bottom right corner y, and 100% sulfide modifier selected from the group consisting of:
A glass substantially free of crystallites defined by a polygon having x, y, and z coordinates for points q, r, and s on a ternary graph wherein 100% germanium sulfide is at the apex x, 100% gallium sulfide/indium sulfide is at the bottom right corner y, and 100% sulfide modifier selected from the group consisting of:
A glass substantially free of crystallites wherein transmission of said glass is over the range of up to about 15 microns and wherein said glass is defined by a polygon having x, y, and z coordinates for points t, u, v, and w on a ternary graph wherein 100% germanium sulfide is at the apex x, 100% sulfide gallium sulfide/indium sulfide is at the bottom right corner y, and 100% modifier selected from the group consisting of:
Dependencies are inferred from the claim text.