Method and composition for the manufacture of gradient index glass

Claim 1

A method of manufacturing gradient index glass comprising the steps of: (1) preparing either (a) a first solution of alkoxysilane with an aqueous source of boron to which an acid catalyst has been added, allowing said solution to cool, adding an aqueous solution of a first metal salt as a source of index modifier cations to form a mixture wherein said first metal salt will yield a high refractive index in said glass and pouring said mixture into a mold, or (b) a second alcoholic solution of alkoxysilane/alkoxyborine, allowing said solution to cool, adding an aqueous solution of a first metal salt as a source of index modifier cations to form a mixture wherein said first metal salt will yield a high refractive index in said glass and pouring said mixture into a mold; (2) allowing sufficient time for said mixture to form a gel; (3) removing said gel from said mold; (4) drying said gel until it is reduced to approximately 2/3 of its size if the alcoholic solution is used; (5) immersing said gel in an aqueous salt bath comprising a second metal salt as a source of index modifier cations wherein said second metal salt will yield a low refractive index in said glass and wherein the metal of said second metal salt comprise elements different from said first metal and wherein said second metal cations have a valence unequal to the index modifier cations of said first metal salt; (6) removing said gel from said bath; (7) drying said gel; (8) dessicating said gel; and (9) densifying said gel at a temperature around the glass transition point temperature.

Claim 2

A method of manufacturing gradient index glass comprising the steps of: (1) preparing either (a) a first solution of alkoxysilane with an aqueous source of boron to which an acid catalyst has been added, allowing said solution to cool, adding an aqueous solution of a first metal salt as a source of index modifier cations to form a mixture wherein said first metal salt will yield a high refractive index in said glass and pouring said mixture into a mold, or (b) a second alcoholic solution of alkoxysilane/alkoxyborine, allowing said solution to cool, adding an aqueous solution of a first metal salt as a source of index modifier cations to form a mixture wherein said first metal salt will yield a high refractive index in said glass and pouring said mixture into a mold; (2) allowing sufficient time for said mixture to form a gel; (3) removing said gel from said mold; (4) drying said gel until it is reduced to approximately 2/3 of its size if the alcoholic solution is used; (5) immersing said gel in an aqueous salt bath comprising a second metal salt as a source of index modifier cations wherein said second metal salt will yield a low refractive index in said glass and wherein the metal of said second metal salt comprise elements different from said first metal and wherein said second metal cations have a valence unequal to the index modifier cations of said first metal salt; (6) removing said gel from said bath; (7) drying said gel; (8) dessicating said gel; and (9) densifying said gel at a temperature around the glass transition point temperature.