Patent ID: 7288495
Filing Date: 2007-10-30
Classification: C03C,G02B

Abstract:
1. A photorefractive glass composition comprising, in weight percent as calculated from the batch, about 65% to about 75% SiO 2 , about 5% to about 12% Al 2 O 3 , about 14-18% Na 2 O, about 0-5% K 2 O, 0 to about 7.5% ZnO, about 0.01 to 0.1% of a weak balanced reducing agent of either Sb 2 O 3 or SnO, about 0.005 to 0.5% Ag, about 0.5 to 1.5% Br, about 1.5 to 3.0% F, about 0-0.01% CeO 2 , and about 0.1 to 0.5% GeO 2 , wherein the glass composition and/or the melting conditions are such that no Ce