Patent US5303255A successfully refreshed from Google Patents.
US5303255A
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US
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Distributed feedback semiconductor laser device and a method of producing the same
Assignee: Sharp Corp
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Filing: 1993-06-29
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Granted: 1994-04-12
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Expires: 2013-06-29
Abstract
Abstract A distributed feedback semiconductor laser device comprising a current blocking structure having a stripe groove, and a diffraction grating formed in the bottom of the stripe groove. The current blocking structure is formed over an active layer for laser oscillation, and it includes an etch stop layer against a groove etching in a lower potion of the current blocking structure. The refractive index distribution in transverse directions inside the stripe groove is controlled by the thickness of the optical guiding layer, enabling oscillation of the fundamental transverse mode.
Inventors
- 👤 Hiroaki Kudo
- 👤 Haruhisa Takiguchi
- 👤 Kazuhiko Inoguchi
- 👤 Chitose Nakanishi
- 👤 Satoshi Sugahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:46
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; H01S5/12; H01S5/1228; H01S5/20; H01S5/22; H01S5/223; H01S5/2231
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
130 words
A distributed feedback semiconductor laser device comprising: a semiconductor substrate; a multilayer structure formed on said semiconductor substrate, said multilayer structure including an active layer for laser oscillation; an optical guiding layer formed on said multilayer structure; a current blocking structure for confining electric currents within a selected region of said active layer, said current blocking structure being formed over said optical guiding layer and having a stripe groove along the cavity length direction, said stripe groove defining said selected region and exposing said optical guiding layer, and said current blocking structure including an etch stop layer in the lower portion of said current blocking structure; and a diffraction grating formed in a region of said optical guiding layer, said region being located at the bottom of said stripe groove.
Claim 2
Dependent Claim
130 words
A distributed feedback semiconductor laser device comprising: a semiconductor substrate; a multilayer structure formed on said semiconductor substrate, said multilayer structure including an active layer for laser oscillation; an optical guiding layer formed on said multilayer structure; a current blocking structure for confining electric currents within a selected region of said active layer, said current blocking structure being formed over said optical guiding layer and having a stripe groove along the cavity length direction, said stripe groove defining said selected region and exposing said optical guiding layer, and said current blocking structure including an etch stop layer in the lower portion of said current blocking structure; and a diffraction grating formed in a region of said optical guiding layer, said region being located at the bottom of said stripe groove.
Claim 3
Dependent Claim
30 words
A distributed feedback semiconductor laser device according to claim 1, wherein said current blocking structure includes an epitaxial growth support layer in the upper portion of said current blocking structure.
Claim 4
Dependent Claim
48 words
A distributed feedback semiconductor laser device according to claim 1, wherein said current blocking structure includes grating support and epitaxial layers in the upper portion of said current blocking structure, and said multilaye structure includes an epitaxial growth support layer in the upper portion of said multilayer structure.
Claim 5
Dependent Claim
34 words
A distributed feedback semiconductor laser device according to claim 1, wherein said multilayer structure includes a first cladding layer formed under said active layer, and a carrier barrier layer formed on said active layer.
Claim 6
Dependent Claim
139 words
A distributed feedback semiconductor laser device comprising: a semiconductor substrate; a multilayer structure formed on said semiconductor substrate, said multilayer structure including an active layer for laser oscillation; an optical guiding layer formed on said multilayer structure; a current blocking structure for confining electric currents within a selected region of said active layer, said current blocking structure being formed over said optical guiding layer and having a stripe groove along the cavity length direction, said stripe groove defining said selected region; and a diffraction grating formed in a region of said optical guiding layer, said region being located at the bottom of said stripe groove and at the widthwise center portion of said stripe groove, said region of said optical guiding layer having a greater thickness than that of regions adjacent to the side walls of said stripe groove.
Claim 7
Dependent Claim
139 words
A distributed feedback semiconductor laser device comprising: a semiconductor substrate; a multilayer structure formed on said semiconductor substrate, said multilayer structure including an active layer for laser oscillation; an optical guiding layer formed on said multilayer structure; a current blocking structure for confining electric currents within a selected region of said active layer, said current blocking structure being formed over said optical guiding layer and having a stripe groove along the cavity length direction, said stripe groove defining said selected region; and a diffraction grating formed in a region of said optical guiding layer, said region being located at the bottom of said stripe groove and at the widthwise center portion of said stripe groove, said region of said optical guiding layer having a greater thickness than that of regions adjacent to the side walls of said stripe groove.
Claim 8
Dependent Claim
134 words
A distributed feedback semiconductor laser device comprising: a semiconductor substrate; a multilayer structure formed on said semiconductor substrate, said multilayer structure including an active layer for laser oscillation; a current blocking structure for confining electric currents within a selected region of said active layer, said current blocking structure being formed on said multilayer structure and having a stripe groove along the cavity length direction, said stripe groove defining said selected region; a diffraction grating formed in a region of said multilayer structure, said region being located at the bottom of said stripe groove; and an optical guiding layer formed on said diffraction grating, said optical guiding layer having a greater thickness at the widthwise center portion of said optical guiding layer than at portions adjacent to the side walls of said stripe shaped groove.
Claim 9
Dependent Claim
134 words
A distributed feedback semiconductor laser device comprising: a semiconductor substrate; a multilayer structure formed on said semiconductor substrate, said multilayer structure including an active layer for laser oscillation; a current blocking structure for confining electric currents within a selected region of said active layer, said current blocking structure being formed on said multilayer structure and having a stripe groove along the cavity length direction, said stripe groove defining said selected region; a diffraction grating formed in a region of said multilayer structure, said region being located at the bottom of said stripe groove; and an optical guiding layer formed on said diffraction grating, said optical guiding layer having a greater thickness at the widthwise center portion of said optical guiding layer than at portions adjacent to the side walls of said stripe shaped groove.
Claim 10
Independent Claim
117 words
A method of fabricating a distributed feedback semiconductor laser device comprising the steps of: forming a multilayer structure on a semiconductor substrate, said multilayer structure including an active layer for laser oscillation; forming an optical guiding layer on said multilayer structure; forming at least one etch stop layer on said optical guiding layer; forming a current blocking layer on said etch stop layer; forming a stripe groove along the cavity length direction in said current blocking layer by selectively etching said current blocking layer, to expose a region of said etch stop layer through said stripe groove; selectively etching said exposed region of said etch stop layer; and forming a diffraction grating in said optical guiding layer.
Claim 11
Independent Claim
117 words
A method of fabricating a distributed feedback semiconductor laser device comprising the steps of: forming a multilayer structure on a semiconductor substrate, said multilayer structure including an active layer for laser oscillation; forming an optical guiding layer on said multilayer structure; forming at least one etch stop layer on said optical guiding layer; forming a current blocking layer on said etch stop layer; forming a stripe groove along the cavity length direction in said current blocking layer by selectively etching said current blocking layer, to expose a region of said etch stop layer through said stripe groove; selectively etching said exposed region of said etch stop layer; and forming a diffraction grating in said optical guiding layer.
Claim 12
Independent Claim
106 words
A method of fabricating a distributed feedback semiconductor laser device comprising the steps of: forming a multilayer structure on a semiconductor substrate, said multilayer structure including an active layer for laser oscillation; forming a current blocking structure on said multilayer structure; forming a stripe groove along the cavity length direction in said current blocking structure, to expose a surface region of said multilayer structure through said stripe groove; forming a diffraction grating in said surface region of said multilayer structure by a photolithography technique using a positive resist; and forming an optical guiding layer on said surface of said multilayer structure to cover said diffraction grating.
Claim 13
Independent Claim
106 words
A method of fabricating a distributed feedback semiconductor laser device comprising the steps of: forming a multilayer structure on a semiconductor substrate, said multilayer structure including an active layer for laser oscillation; forming a current blocking structure on said multilayer structure; forming a stripe groove along the cavity length direction in said current blocking structure, to expose a surface region of said multilayer structure through said stripe groove; forming a diffraction grating in said surface region of said multilayer structure by a photolithography technique using a positive resist; and forming an optical guiding layer on said surface of said multilayer structure to cover said diffraction grating.
Claim 14
Independent Claim
101 words
A method of fabricating a distributed feedback semiconductor laser device comprising the steps of: forming a multilayer structure on a semiconductor substrate, said multilayer structure including an active layer for a laser oscillation; forming an optical guiding layer on said multilayer structure; forming a current blocking structure on said multilayer structure; forming a stripe groove along the cavity length direction in said current blocking layer, to expose a surface region of said optical guiding layer through said stripe groove; and forming a diffraction grating in said surface region of said optical guiding layer by a photolithography technique using a negative resist.
Claim 15
Independent Claim
101 words
A method of fabricating a distributed feedback semiconductor laser device comprising the steps of: forming a multilayer structure on a semiconductor substrate, said multilayer structure including an active layer for a laser oscillation; forming an optical guiding layer on said multilayer structure; forming a current blocking structure on said multilayer structure; forming a stripe groove along the cavity length direction in said current blocking layer, to expose a surface region of said optical guiding layer through said stripe groove; and forming a diffraction grating in said surface region of said optical guiding layer by a photolithography technique using a negative resist.
Claim 16
Dependent Claim
144 words
An AlGaAs type distributed feedback semiconductor laser device comprising: a semiconductor substrate; a multilayer structure formed on said semiconductor substrate, said multilayer structure including an active layer for laser oscillation and a carrier barrier layer for reducing carrier-overflows from said active layer; an optical guiding layer formed on said multilayer structure; a current blocking structure for confining electric currents within a selected region of said active layer, said current blocking structure being formed over said optical guiding layer and having a stripe groove along the cavity length direction, said stripe groove defining said selected region and exposing said optical guiding layer, and said current blocking structure including an etch stop layer in the lower portion of said current blocking structure; and a diffraction grating formed in a region of said optical guiding layer, said region being located at the bottom of said stripe groove.
Claim 17
Dependent Claim
144 words
An AlGaAs type distributed feedback semiconductor laser device comprising: a semiconductor substrate; a multilayer structure formed on said semiconductor substrate, said multilayer structure including an active layer for laser oscillation and a carrier barrier layer for reducing carrier-overflows from said active layer; an optical guiding layer formed on said multilayer structure; a current blocking structure for confining electric currents within a selected region of said active layer, said current blocking structure being formed over said optical guiding layer and having a stripe groove along the cavity length direction, said stripe groove defining said selected region and exposing said optical guiding layer, and said current blocking structure including an etch stop layer in the lower portion of said current blocking structure; and a diffraction grating formed in a region of said optical guiding layer, said region being located at the bottom of said stripe groove.
Claim 18
Dependent Claim
32 words
An AlGaAs type distributed feedback semiconductor laser device according to claim 10, wherein said current blocking structure includes an expitaxial growth support layer in the upper portion of said current blocking structure.
Claim 19
Dependent Claim
50 words
An AlGaAs type distributed feedback semiconductor laser device according to claim 10, wherein said current blocking structure includes grating support and epitaxial layers in the upper portion of said current blocking structure, and said multilayer structure includes an epitaxial growth support layer in the upper portion of said multilayer structure;
Claim 20
Dependent Claim
36 words
An AlGaAs type distributed feedback semiconductor laser device according to claim 10, wherein said multilayer structure includes a first cladding layer formed under said active layer, and said carrier barrier layer formed on said active layer.
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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) | 1997-04-11 | 1997-10-11 | 1998-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-04-11 | 2001-10-11 | 2002-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-04-11 | 2005-10-11 | 2006-04-12 | $7700.00 | Window Closed / Lapsed |