US3630765A
Expired / Lapsed
US
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Photochromic glass containing tantalum oxide for optical fiber fabrication
Assignee: Corning Glass Works
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Filing: 1969-02-24
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Granted: 1971-12-28
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Expires: 1989-02-24
Abstract
Abstract This invention relates to photochromic glass compositions containing about 10-50 percent by weight Ta2O5 which have refractive indices higher than about 1.52, and, preferably, higher than about 1.58, thereby rendering them especially suitable as a core glass in the production of photochromic optical fibers.
Inventors
- 👤 Roger J Araujo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:23
CPC Classifications
C; C03; C03C; C03C13/00; C03C13/04; C03C13/045; C03C13/046; C03C3/00; C03C3/04; C03C3/076; C03C3/089; C03C4/00; C03C4/04; C03C4/06; Y; Y10; Y10S; Y10S501/00; Y10S501/90
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
41 words
A transparent photochromic glass according to claim 1 wherein the analyzed silver content in the glass is less than about 0.7 percent by weight and the analyzed total halogen content in the glass is less than about 0.6 percent by weight.
Claim 2
Dependent Claim
69 words
A transparent photochromic glass having an index of refraction greater than 1.52 consisting essentially, by weight on the oxide basis as calculated from the batch, of about 30- 60% SiO2, 0- 12% A12O3, 5- 20 percent B2O3, 10- 30% Ta2O5, 5- 15% total of Li2O, Na2O, K2O, Rb2O, and Cs2O, 0.3- 0.8% C1, 0- 0.2% Br, 0.2- 0.6% Ag, 0- 1% F, 0.01- 0.1% CuO, and 0- 0.2% As2O3.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |