Patent US5488507A successfully refreshed from Google Patents.
US5488507A
Expired / Lapsed
US
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Semiconductor optical amplifier having reduced polarization dependence
Assignee: Canon Inc
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Filing: 1994-09-15
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Granted: 1996-01-30
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Expires: 2014-09-15
Abstract
Abstract A semiconductor optical amplifier comprises a substrate and an active layer constructed as a quantum well structure. The active layer includes a plurality of well layers and a plurality of barrier layers which are alternately layered. The composition of each well layer is such that the well layers have different quantum levels. The barrier layers are subjected to biaxial strain to shift the energy band structures so as to eliminate the polarization dependency of optical gain in the active region.
Inventors
- 👤 Michiyo Nishimura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:04
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/50; H01S5/5009; B; B82; B82Y; B82Y20/00; H01S5/30; H01S5/34; H01S5/3403; H01S5/3404; H01S5/3407
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
80 words
A semiconductor optical device comprising: a substrate; and an active layer of quantum well structure, said active layer including a plurality of well layers and a plurality of barrier layers which are alternately layered, said well layers having different quantum levels and said barrier layers being respectively subjected to biaxial strain, wherein each of said plurality of well layers has a polarization dependency and said plurality of well layers compensate for each polarization dependency of each other or one another.
Claim 2
Dependent Claim
80 words
A semiconductor optical device comprising: a substrate; and an active layer of quantum well structure, said active layer including a plurality of well layers and a plurality of barrier layers which are alternately layered, said well layers having different quantum levels and said barrier layers being respectively subjected to biaxial strain, wherein each of said plurality of well layers has a polarization dependency and said plurality of well layers compensate for each polarization dependency of each other or one another.
Claim 3
Dependent Claim
20 words
A semiconductor optical device according to claim 1, wherein said barrier layers are respectively subjected to a predetermined biaxial strain.
Claim 4
Dependent Claim
35 words
A semiconductor optical device according to claim 1, wherein no well layers are subjected to biaxial strain and said well layers are different from each other in at least one of composition and well width.
Claim 5
Dependent Claim
102 words
A semiconductor optical device according to claim 1, wherein a ground level in a valence band of one of at least two well layers is a level of heavy holes, a ground level in the valence band of the other of the at least two well layers is a level of light holes, and inter-band transitions between an electron level in a conduction band and the level of heavy holes in said one well layer and between an electron level in a conduction band and the level of light holes in said the other well layer occur at substantially the same wavelength.
Claim 6
Dependent Claim
41 words
A semiconductor optical device according to claim 4, wherein a ground level in a valence band of still another well layer is a level of light holes for compensating for an optical transition of light holes during of high-density carrier injection.
Claim 7
Dependent Claim
26 words
A semiconductor optical device according to claim 1, wherein said device is constructed as a semiconductor optical amplifier for imparting gain to input light from outside.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-29 | 1999-07-31 | 2000-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-29 | 2003-07-31 | 2004-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-29 | 2007-07-31 | 2008-01-30 | $7700.00 | Window Closed / Lapsed |