Optical glass
AssigneeBay Glass Research
InventorsDonald M. McPherson, Steven C. Murray
Life of this patent
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Abstract
High rare-earth content glasses (Ln.sub.2 O.sub.3 .gtoreq.20 mol %) have applications as high optical density wavelength-selective filters, faraday rotators, scintillation glasses and high index glasses. New glasses are formed by adding TiO.sub.2 to the system SiO.sub.2 --B.sub.2 O.sub.3 --Al.sub.2 O.sub.3 --Ln.sub.2 O.sub.3. These glasses have improved optical properties, extended glass formation range and have superior resistance to devitrification. In some embodiments TiO.sub.2 can fully replace the Al.sub.2 O.sub.3. In additional embodiments, SiO.sub.2 can be completely removed from the glass.
Claims14
An optical glass consisting essentially of, in mole percent, 0-40% SiO.sub.2, 5-30% TiO.sub.2, 10-60% B.sub.2 O.sub.3, 0-30% Al.sub.2 O.sub.3, 0-25% GeO.sub.2, 0-25% Y.sub.2 O.sub.3, 0-10% ZrO.sub.2, 0-20% Ga.sub.2 O.sub.3, 0-10% WO.sub.3, 0-9% MoO.sub.3, 0-8% ZnO, 0-7% SnO.sub.2 0-5% Ta.sub.2 O.sub.5, and 20-42% Ln.sub.2 O.sub.3, where the rare-earth oxide, Ln.sub.2 O.sub.3 is one or more selected from the following group:
- Er.sub.2 O.sub.3, Nd.sub.2 O.sub.3, Dy.sub.2 O.sub.3, Sm.sub.2 O.sub.3, Ho.sub.2 O.sub.3, La.sub.2 O.sub.3, Gd.sub.2 O.sub.3, Yb.sub.2 O.sub.3, Tb.sub.2 O.sub.3, Eu.sub.2 O.sub.3, Tm.sub.2 O.sub.3, Pr.sub.2 O.sub.3, Ce.sub.2 O.sub.3 ;
- and with the compositional limits, in mole percent, further defined by the following equalities;
- SiO.sub.2 +B.sub.2 O.sub.3 +GeO.sub.2 +P.sub.2 O.sub.5 .gtoreq.+%, Ln.sub.2 O.sub.3 +Y.sub.2.sub.O 20-42%, TiO.sub.2 +A.sub.2 O.sub.3 +ZrO.sub.2 +ZnO+SnO.sub.2 +Ga.sub.2 O.sub.3 +Nb.sub.2 O.sub.5 .revreaction.Ta.sub.2 O.sub.5 +WO.sub.3 +MoO.sub.3 =10-37%, TiO.sub.2 +Al.sub.2 O.sub.3 =10-36%, TiO.sub.2 +SiO.sub.2 (with GeO.sub.2 =0) =15-75%, TiO.sub.2 +SiO.sub.2 +GeO.sub.2 =29-60%, and TiO.sub.2 +SiO.sub.2 +GeO.sub.2 +B.sub.2 O.sub.3 =48-80%.
A borate glass consisting essentially of, in mole percent, 10-60% B.sub.2 O.sub.3, 10-30% TiO.sub.2, and 15-35% Ln.sub.2 O.sub.3, where the rare-earth oxide, Ln.sub.2 O.sub.3 is one or more selected from the following group:
- Er.sub.2 O.sub.3, Nd.sub.2 O.sub.3, Dy.sub.2 O.sub.3, Sm.sub.2 O.sub.3, Ho.sub.2 O.sub.3, La.sub.2 O .sub.3, Gd.sub.2 O.sub.3, Yb.sub.2 O.sub.3, Tb.sub.2 O.sub.3, EU.sub.2 O.sub.3, Tm.sub.2 O.sub.3, Pr.sub.2 O.sub.3, Ce.sub.2 O.sub.3.
Dependencies are inferred from the claim text.