US4999841A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor lasers
Assignee: Rohm Co Ltd
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Filing: 1990-01-24
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Granted: 1991-03-12
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Expires: 2010-01-24
Abstract
Abstract The invention is directed to a semiconductor laser wherein the first embodiment is characterized in that the first upper portion cladding layer is assumed to be a double layer construction, the upper layer portion is assumed to be higher in carrier concentration than the lower layer portion, the series resistance component is restrained, so that the sequential direction voltage V F may be lowered without damaging the other characteristics such as oscillation start current I th and so on.
Inventors
- 👤 Hajime Sakiyama
- 👤 Haruo Tanaka
- 👤 Masato Mushiage
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:47
CPC Classifications
H; H10; H10H; H10H20/00; H10H20/01; H10H20/011; H10H20/013; H01; H01S; H01S5/00; H01S5/20; H01S5/22; H01S5/223; H01S5/2231; H01S5/30; H01S5/32; H01S5/3211; H01S5/323; H01S5/32308; Y; Y10; Y10S; Y10S148/00; Y10S148/071; Y10S148/094; Y10S148/095
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
114 words
A semiconductor laser, wherein a lower portion cladding layer, an active layer, a first upper portion cladding layer, a light absorption layer, an evaporation preventing layer are laminated in order on a semiconductor substrate, a stripe groove which reaches a first upper portion cladding layer from the evaporation preventing layer is formed, a second upper portion cladding layer and a cap layer are laminated so as to cover the stripe groove, electrodes are respectively formed on the semiconductor substrate and the cap layer, and the first upper portion cladding layer is of a double construction of which the upper layer portion is rendered to be higher in carrier concentration than the lower layer portion.
Claim 2
Dependent Claim
114 words
A semiconductor laser, wherein a lower portion cladding layer, an active layer, a first upper portion cladding layer, a light absorption layer, an evaporation preventing layer are laminated in order on a semiconductor substrate, a stripe groove which reaches a first upper portion cladding layer from the evaporation preventing layer is formed, a second upper portion cladding layer and a cap layer are laminated so as to cover the stripe groove, electrodes are respectively formed on the semiconductor substrate and the cap layer, and the first upper portion cladding layer is of a double construction of which the upper layer portion is rendered to be higher in carrier concentration than the lower layer portion.
Claim 3
Dependent Claim
108 words
A semiconductor laser, wherein a lower portion cladding layer, an active layer, a first upper portion cladding layer, a light absorption layer, an evaporation preventing layer are laminated in order on a semiconductor substrate, a stripe groove which reaches a first upper portion cladding layer from the evaporation preventing layer is formed, a second upper portion cladding layer and a cap layer are laminated so as to cover the stripe groove, electrodes are respectively formed on the semiconductor substrate and the cap layer, and the carrier concentration of the second upper portion cladding layer is made higher than the carrier concentration of the first upper portion cladding layer.
Claim 4
Dependent Claim
108 words
A semiconductor laser, wherein a lower portion cladding layer, an active layer, a first upper portion cladding layer, a light absorption layer, an evaporation preventing layer are laminated in order on a semiconductor substrate, a stripe groove which reaches a first upper portion cladding layer from the evaporation preventing layer is formed, a second upper portion cladding layer and a cap layer are laminated so as to cover the stripe groove, electrodes are respectively formed on the semiconductor substrate and the cap layer, and the carrier concentration of the second upper portion cladding layer is made higher than the carrier concentration of the first upper portion cladding layer.
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) | 1994-03-11 | 1994-09-10 | 1995-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-03-11 | 1998-09-10 | 1999-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-03-11 | 2002-09-10 | 2003-03-12 | $7700.00 | Window Closed / Lapsed |