US4794608A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor laser device
Assignee: Panasonic Holdings Corp
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Filing: 1985-03-05
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Granted: 1988-12-27
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Expires: 2005-03-05
Abstract
Abstract A semiconductor laser device of a new monolithic structure has a long transparent optical waveguide used as a passive cavity directly coupled with an active cavity possessing a gain in the direction of the optical axis of the active cavity on a compound semiconductor substrate. The device is intended to satisfy all four characteristics, which are; (1) stable single longitudinal mode oscillation; (2) narrow spectral linewidth; (3) suppression of wavelength chirping due to current modulation; and (4) low noise and to be applied as a light source for optical fiber communication, optical information processing or the like.
Inventors
- 👤 Toshihiro Fujita
- 👤 Jun Ohya
- 👤 Kenichi Matsuda
- 👤 Hiroyuki Serizawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:19
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/0014; H01S5/10; H01S5/1021; H01S5/02; H01S5/026; H01S5/0265; H01S5/06; H01S5/062; H01S5/06209; H01S5/06213; H01S5/0625; H01S5/06255; H01S5/06258; H01S5/065; H01S5/0651; H01S5/0653; H01S5/0655; H01S5/1025; H01S5/12; H01S5/125; H01S5/14; H01S5/141; H01S5/142
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
204 words
A semiconductor laser device comprising: a semiconductor substrate; an active cavity formed on said semiconductor substrate; and a passive cavity formed on said semiconductor substrate, said active and passive cavities being integrally formed on sa id semiconductor substrate with monolithic structure and coupled in the direction of optical axes of said cavities, said active cavity including, an active layer for emitting light therefrom, clad layers for confining said light into said active layer, and electrodes for injecting current into said active layer, said passive cavity including, a waveguide layer for transferring therethrough the light emitted in said active cavity, and clad layers for ocnfining said light to said waveguide layer, said active and passive cavities having rectangular waveguide structure to confine said light in a plane perpendicular to said direction of optical axes of said cavities, resonator means for laser oscillation of said semiconductor laser device, the ratio L 0 /L 1 of optical length L 0 of said passive cavity to optical length L 1 of said active cavity being set in a range of L 0 /L 1 ≧0.5, whereby the light emitted in said active cavity is transferred through said passive cavity and reflected and fed back to said active cavity.
Claim 2
Dependent Claim
204 words
A semiconductor laser device comprising: a semiconductor substrate; an active cavity formed on said semiconductor substrate; and a passive cavity formed on said semiconductor substrate, said active and passive cavities being integrally formed on sa id semiconductor substrate with monolithic structure and coupled in the direction of optical axes of said cavities, said active cavity including, an active layer for emitting light therefrom, clad layers for confining said light into said active layer, and electrodes for injecting current into said active layer, said passive cavity including, a waveguide layer for transferring therethrough the light emitted in said active cavity, and clad layers for ocnfining said light to said waveguide layer, said active and passive cavities having rectangular waveguide structure to confine said light in a plane perpendicular to said direction of optical axes of said cavities, resonator means for laser oscillation of said semiconductor laser device, the ratio L 0 /L 1 of optical length L 0 of said passive cavity to optical length L 1 of said active cavity being set in a range of L 0 /L 1 ≧0.5, whereby the light emitted in said active cavity is transferred through said passive cavity and reflected and fed back to said active cavity.
Claim 3
Dependent Claim
23 words
A semiconductor laser device of claim 1, wherein said active cavity has a bandgap which is smaller than that of said waveguide layer.
Claim 4
Dependent Claim
56 words
The semiconductor laser device of claim 2, wherein said resonator means comprises a first resonator surface and a second resonator surface, said first resonator surface being formed on said active surface, said first resonator from said passive cavity and said second resonator surface being formed on said passive cavity and located away from said active cavity.
Claim 5
Dependent Claim
18 words
The semiconductor laser device of claim 3, wherein said second resonator surface has a reflection film coated thereon.
Claim 6
Dependent Claim
50 words
The semiconductor laser device of claim 1, wherein said active cavity includes a first facet close to said passive cavity and said passive cavity includes a second facet close to said active cavity, said first facet and said second facet being spaced from each other to define a gap therebetween.
Claim 7
Dependent Claim
16 words
The semiconductor laser device of claim 5, wherein an insulator at least partially fills said gap.
Claim 8
Dependent Claim
19 words
The semiconductor laser device of claim 5, wherein said gap extends through said waveguide layer and said active layer.
Claim 9
Dependent Claim
20 words
The semiconductor laser device of claim 5, wherein said gap extends partially through said waveguide layer and said active layer.
Claim 10
Dependent Claim
20 words
The semiconductor laser device of claim 5, wherein said gap extends up to said waveguide layer and said active layer.
Claim 11
Dependent Claim
21 words
The semiconductor laser device of claim 1, wherein said waveguide layer is disposed between said active cavity and said semiconductor substrate.
Claim 12
Dependent Claim
29 words
The semiconductor laser device of claim 1, wherein said passive cavity includes a load layer stripe, said waveguide layer being between said load layer stripe and said semiconductor substrate.
Claim 13
Dependent Claim
25 words
The semiconductor laser device of claim 1, wherein said passive cavity includes an electrode capable of electrically controlling the effective index of said waveguide layer.
Claim 14
Dependent Claim
23 words
The semiconductor laser device of claim 1, wherein said waveguide layer has a multiple-quantum-well structure which is the same as said active layer.
Claim 15
Dependent Claim
21 words
The semiconductor laser device of claim 1, wherein said resonator means includes means in said active cavity for providing distributed feedback.
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) | 1991-12-27 | 1992-06-27 | 1992-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-27 | 1996-06-27 | 1996-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-27 | 2000-06-27 | 2000-12-27 | $7700.00 | Window Closed / Lapsed |