Patent US2825550A successfully refreshed from Google Patents.
Patent US4815089A successfully refreshed from Google Patents.
US4815089A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor laser
Assignee: Sharp Corp
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Filing: 1985-05-09
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Granted: 1989-03-21
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Expires: 2005-05-09
Abstract
Abstract A semiconductor laser includes a front mirror facet and a rear mirror facet. An Al 2 O 3 film coating is formed on the front mirror facet by electron beam evaporation so that the front mirror facet has a reflectance between 10 and 20%. A multi-layered coating is formed on the rear mirror facet so that the rear mirror facet has a reflectance higher than 90%.
Inventors
- 👤 Nobuyuki Miyauchi
- 👤 Shigeki Maei
- 👤 Osamu Yamamoto
- 👤 Taiji Morimoto
- 👤 Hiroshi Hayashi
- 👤 Saburo Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:31
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/02; H01S5/028; H01S5/20; H01S5/22; H01S5/223; H01S5/2232; H01S5/2237
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
93 words
In a semiconductor laser including a semiconductor substrate, an active layer sandwiched by a pair of cladding layers disposed on said substrate, and front and rear facets the improvement comprising: a first coating formed on said front facet such that said front facet exhibits a reflectivity in the range of 10 to 20%; and a second coating formed on said rear facet such that said rear facet exhibits a reflectivity of greater than 90%, said first and second coatings enabling said laser to be operable over a wide range of output power levels.
Claim 2
Dependent Claim
93 words
In a semiconductor laser including a semiconductor substrate, an active layer sandwiched by a pair of cladding layers disposed on said substrate, and front and rear facets the improvement comprising: a first coating formed on said front facet such that said front facet exhibits a reflectivity in the range of 10 to 20%; and a second coating formed on said rear facet such that said rear facet exhibits a reflectivity of greater than 90%, said first and second coatings enabling said laser to be operable over a wide range of output power levels.
Claim 3
Dependent Claim
44 words
In a semiconductor laser as claimed in claim 1, further comprising a current blocking layer disposed between said semiconductor substrate and one of said pair of cladding layers, wherein an inner stripe is formed in said current blocking layer to form a current path.
Claim 4
Dependent Claim
24 words
In a semiconductor laser as claimed in claim 2, wherein said coating formed on said front facet comprises an Al 2 O 3 film.
Claim 5
Dependent Claim
146 words
A semiconductor laser operable over a wide range of output power levels, comprising: a semiconductor substrate; a current blocking layer disposed on said substrate; an active layer sandwiched by a pair of cladding layers disposed on said current blocking layer; a cap layer disposed on an upper cladding layer; a first electrode disposed on said cap layer; a second electrode disposed on said substrate on a surface opposite to said current blocking layer; a front facet; a rear facet; a first coating formed on said front face such that said front facet exhibits a reflectivity in the range of 10 to 20%; and a second coating formed on said rear facet such that said rear facet exhibits a reflectivity of greater than 90%; said reflectivity of said front facet ensuring a constant beam waist position of said laser over a wide range of output power levels.
Claim 6
Dependent Claim
146 words
A semiconductor laser operable over a wide range of output power levels, comprising: a semiconductor substrate; a current blocking layer disposed on said substrate; an active layer sandwiched by a pair of cladding layers disposed on said current blocking layer; a cap layer disposed on an upper cladding layer; a first electrode disposed on said cap layer; a second electrode disposed on said substrate on a surface opposite to said current blocking layer; a front facet; a rear facet; a first coating formed on said front face such that said front facet exhibits a reflectivity in the range of 10 to 20%; and a second coating formed on said rear facet such that said rear facet exhibits a reflectivity of greater than 90%; said reflectivity of said front facet ensuring a constant beam waist position of said laser over a wide range of output power levels.
Claim 7
Dependent Claim
22 words
The semiconductor laser of claim 4, wherein an inner stripe is formed in said current blocking layer to form a current path.
Claim 8
Dependent Claim
17 words
The semiconductor laser of claim 4, wherein said first coating comprises an Al 2 O 3 film.
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) | 1992-03-20 | 1992-09-19 | 1993-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-20 | 1996-09-19 | 1997-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-20 | 2000-09-19 | 2001-03-21 | $7700.00 | Window Closed / Lapsed |