US4705346A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thin film type optical device
Assignee: Canon Inc
•
Filing: 1985-05-13
•
Granted: 1987-11-10
•
Expires: 2005-05-13
Abstract
Abstract A thin film type optical device comprises a substrate formed of lithium niobate crystal or lithium tantalate crystal, and a light waveguide path layer comprising protons introduced into the surface of the substrate and having a refractive index higher than that of the substrate. The absorption peak of the infrared absorption spectrum of OH radical by the protons in the light waveguide path layer exists in the range of wave number 3480 cm -1 to 3503 cm -1 .
Inventors
- 👤 Mamoru Miyawaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 15:11
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/122
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
88 words
A thin film type optical device comprising: a substrate formed of lithium niobate crystal or lithium tantalate crystal; and a light waveguide path layer comprising protons introduced into the surface of said substrate in exchange for the lithium atoms in said crystal and having a refractive index higher than that of said substrate, the absorption peak of the infrared absorption spectrum of OH radical by the protons in said light waveguide path layer existing in the range of wave number 3480 cm -1 to 3503 cm -1 .
Claim 2
Dependent Claim
88 words
A thin film type optical device comprising: a substrate formed of lithium niobate crystal or lithium tantalate crystal; and a light waveguide path layer comprising protons introduced into the surface of said substrate in exchange for the lithium atoms in said crystal and having a refractive index higher than that of said substrate, the absorption peak of the infrared absorption spectrum of OH radical by the protons in said light waveguide path layer existing in the range of wave number 3480 cm -1 to 3503 cm -1 .
Claim 3
Dependent Claim
21 words
A thin film type optical device according to claim 1, wherein said protons are heat-diffused on the surface of said substrate.
Claim 4
Dependent Claim
21 words
A thin film type optical device according to claim 1, wherein a metal is heat-diffused on the surface of said substrate.
Claim 5
Dependent Claim
22 words
A thin film type optical device according to claim 1, wherein lithium oxide is externally diffused on the surface of said substrate.
Claim 6
Dependent Claim
29 words
A thin film type optical device according to claim 1, further comprising a comb type electrode formed on said light waveguide path layer and exciting an elastic surface wave.
Claim 7
Dependent Claim
32 words
A thin film type optical device according to claim 1, further comprising a comb type electrode formed on said light waveguide path layer and producing a phase grating by the electro-optical effect.
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) | 1990-11-09 | 1991-05-11 | 1991-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-09 | 1995-05-11 | 1995-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-09 | 1999-05-11 | 1999-11-10 | $7700.00 | Window Closed / Lapsed |