Patent US5579155A successfully refreshed from Google Patents.
US5579155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor optical amplifier
Assignee: NEC Corp
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Filing: 1994-11-10
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Granted: 1996-11-26
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Expires: 2014-11-10
Abstract
Abstract A semiconductor optical amplifier having a large gain and a high saturation optical output power has a uniform cross-section of an active layer. In the semiconductor optical amplifier, the band gap wavelength of the active layer in the vicinity of the light-emitting end is shorter than that in the vicinity of the light-receiving end. The active layer may have a multiple quantum well structure, or the active layer may have a tesile-strained (compressively strained) multiple quantum well structure in which the absolute strain quantity in the vicinity of the light-emitting end is larger than that in the vicinity of the light-receiving end.
Inventors
- 👤 Mitsuhiro Kitamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:43
CPC Classifications
B; B82; B82Y; B82Y20/00; H; H01; H01S; H01S5/00; H01S5/50; H01S5/10; H01S5/1053; H01S5/1057; H01S5/1064; H01S5/20; H01S5/22; H01S5/227; H01S5/2272; H01S5/30; H01S5/34; H01S5/343; H01S5/34306; H01S5/3434; H01S5/5009
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
A semiconductor optical amplifier comprising a substrate, at least one semiconductor active layer, formed overlying said substrate, for amplifying a signal light received through a light-receiving end of said active layer to emit the signal light through a light-emitting end of the active layer, said active layer having a first band gap wavelength in the vicinity of said light-receiving end and a second band gap wavelength in the vicinity of said light-emitting end, said first band gap wavelength being longer than said second band gap wavelength.
Claim 2
Dependent Claim
86 words
A semiconductor optical amplifier comprising a substrate, at least one semiconductor active layer, formed overlying said substrate, for amplifying a signal light received through a light-receiving end of said active layer to emit the signal light through a light-emitting end of the active layer, said active layer having a first band gap wavelength in the vicinity of said light-receiving end and a second band gap wavelength in the vicinity of said light-emitting end, said first band gap wavelength being longer than said second band gap wavelength.
Claim 3
Dependent Claim
33 words
A semiconductor optical amplifier as defined in claim 1 further comprising a buffer layer sandwiched between said active layer and said substrate, said buffer layer and said active layer form a mesa structure.
Claim 4
Dependent Claim
45 words
A semiconductor optical amplifier as defined in claim. 2 further comprising a mask piece extending substantially parallel to said buffer layer, said mask piece having a first end adjacent to said light-emitting end smaller in width than a second end adjacent to said light-receiving end.
Claim 5
Dependent Claim
21 words
A semiconductor optical amplifier as defined in claim 3 wherein said buffer layer and said active layer are grown by epitaxy.
Claim 6
Dependent Claim
26 words
A semiconductor optical amplifier as defined in claim 1 wherein said at least active layer is implemented by at least one layer of multiple quantum well.
Claim 7
Dependent Claim
39 words
A semiconductor optical amplifier as defined in claim 5 wherein said multiple quantum well is of tensile strained type and has an absolute strain value in the vicinity of light-emitting end larger than in the vicinity of light-receiving end.
Claim 8
Dependent Claim
19 words
A semiconductor optical amplifier as defined in claim 5 wherein said multiple quantum well is of compressively strained type.
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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) | 1999-11-26 | 2000-05-27 | 2000-11-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-26 | 2004-05-27 | 2004-11-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-26 | 2008-05-27 | 2008-11-26 | $7700.00 | Window Closed / Lapsed |