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US 4,731,348 AGranted
Aluminosilicate optical glass
AssigneeBatelle Memorial Institute
InventorCarlos Gonzales-Oliver
Life of this patent
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Abstract
Optical glasses based on silica and alumina, rich in modifying metals such as silver, thallium and cesium. The exchange by cathodic migration in a melted salt bath of said modifying metals by metals such as K, Na and Li, exchange which leads to a corresponding variation of the refraction index of the glass according to a certain predetermined profile, is performed very efficiently and rapidly. Such an exchange is performed either on the finished glass or on a microporous form thereof.
Claims6
An aluminosilicate optical glass without boron oxide, characterized in that it contains:
- (a) 60-95 mole % of silica;
- (b) at least 2 mole % of alumina;
- and
- (c) at least 2 mole % of a modifying metal component selected from the group consisting of
- (i) an oxide of silver,
- (ii) a mixture of an oxide of silver and an oxide of thallium,
- (iii) a mixture of a oxide of silver and an oxide of cesium, and
- (iv) a mixture of an oxide of silver, an oxide of thallium and an oxide of cesium.
5 more elements
Dependencies are inferred from the claim text.