UV photosensitive melted germano-silicate glasses
AssigneeCorning Incorporated
InventorsNicholas F. Borelli, George B. Hares, Charlene M. Smith
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Abstract
The present invention relates generally to UV (ultraviolet) photosensitive bulk glass, and particularly to batch meltable alkali boro-alumino-silicate glasses. The photosensitive bulk glass of the invention exhibits photosensitivity to UV wavelengths below 250 nm. The photosensitivity of the alkali boro-alumino-silicate bulk glass to UV wavelengths below 250 nm provide for the making of refractive index patterns in the glass. With a radiation source below 250 nm, such as a laser, refractive index patterns are formed in the glass. The inventive photosensitive optical refractive index pattern forming bulk glass allows for the formation of patterns in glass and devices which utilize such patterned glass.
Claims65
A below 250 nm photosensitizable glass said photosensitizable glass comprising 40-80 mole % SiO2, 2-15 mole % GeO2, 10-36 mole % B2O3, 1-6 mole % Al2O3, and 2-10 mole % R2O wherein R is an alkali metal.
A molecular hydrogen loadable photosensitive bulk glass, said glass comprised of an alkali metal boro-alumino-silicate glass having a melting temperature≦1650° C., said alkali metal boro-alumino-silicate glass having a batch composition comprising ≦85 mole % SiO2, ≧10 mole % B2O3, ≧2 mole % GeO2, and a combined alkali metal and alumina content <20 mole % Al2O3+alkali metal, said glass having a molecular hydrogen loadable level of at least 1018 H2 molecules/cm3.
A photosensitive glass optical refractive index pattern preform for use with UV light in the formation of refractive index patterns, said preform comprised of an alkali metal boro-alumino-silicate glass with an absorption less than 20 dB/cm at a wavelength of 250 nm, said refractive index pattern preform having a UV wavelength inducable modulated refractive index Δn level>10−5 with a molecular hydrogen level of at least 1018 H2 molecules/cm3.
Dependencies are inferred from the claim text.