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US4745616A
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Semiconductor laser device with a diffraction grating
Assignee: Sharp Corp
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Filing: 1986-02-19
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Granted: 1988-05-17
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Expires: 2006-02-19
Abstract
Abstract A semiconductor laser device comprising a GaAlAs first cladding layer, a Ga 1-x Al x As (0≦x≦0.4) active layer for laser oscillation, an In 1-y Ga y P 1-z As z (z=2.04y-1.04, and 0≦z≦1) optical guiding layer with a diffraction grating thereon, a GaAlAs buffer layer disposed between said active layer and said optical guiding layer, and a GaAlAs second cladding layer, the width of the forbidden band of said buffer layer being greater than that of the active layer and smaller than that of the optical guiding layer.
Inventors
- 👤 Shinji Kaneiwa
- 👤 Haruhisa Takiguchi
- 👤 Toshihiko Yoshida
- 👤 Sadayoshi Matsui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:21
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; H01S5/12
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
106 words
A semiconductor laser device having an optical structure comprising: a GaAlAs first cladding layer, an Ga 1-x Al x As (0≦x≦0.4) active layer for laser oscillation formed on said first cladding layer, a GaAlAs buffer layer formed on said active layer, an In 1-y Ga y P 1-z As z (z=2.04y-1.04, and 0≦z≦1) optical guiding layer having a diffraction grating thereon formed on said buffer layer, and a GaAlAs second cladding layer formed on said optical guiding layer, wherein the width of the forbidden band of said buffer layer is greater than that of said active layer and smaller than that of said optical guiding layer.
Claim 2
Dependent Claim
106 words
A semiconductor laser device having an optical structure comprising: a GaAlAs first cladding layer, an Ga 1-x Al x As (0≦x≦0.4) active layer for laser oscillation formed on said first cladding layer, a GaAlAs buffer layer formed on said active layer, an In 1-y Ga y P 1-z As z (z=2.04y-1.04, and 0≦z≦1) optical guiding layer having a diffraction grating thereon formed on said buffer layer, and a GaAlAs second cladding layer formed on said optical guiding layer, wherein the width of the forbidden band of said buffer layer is greater than that of said active layer and smaller than that of said optical guiding layer.
Claim 3
Dependent Claim
76 words
A semiconductor laser device according to claim 1, wherein the forbidden band widths of said active layer, said buffer layer, said optical guiding layer, said first cladding layer, and second cladding layer are E 3 , E 9 , E 4 , E 2 , and E 5 , respectively, and the following relationships therebetween are achieved: E.sub.3 <E.sub.9 [≦E.sub.4 <E.sub.2 & E.sub.5 ], <E.sub.4 <E.sub.2 &E.sub.5, and [E.sub.2 E.sub.5 ] E.sub.2 &E.sub.5 -E.sub.3 ≧0.3 eV.
Claim 4
Dependent Claim
18 words
A semiconductor laser device according to claim 1, wherein the oscillation wavelength thereof is 890 nm or less.
Claim 5
Dependent Claim
22 words
A semiconductor laser device according to claim 3, wherein the oscillation wavelength thereof is in the range of 660 to 890 nm.
Claim 6
Dependent Claim
18 words
A semiconductor laser device according to claim 2, wherein the oscillation wavelength thereof is 890 nm or less.
Claim 7
Dependent Claim
44 words
A semiconductor laser device according to claim 4, wherein said optical guiding layer comprises In 1-y Ga y P 1-z As z (0.68≦y≦1, 0.34≦z≦1, and z=2.04y-1.04), and wherein said first cladding layer and said second cladding layer comprise Ga 1-x Al x As (0.2≦x≦1).
Claim 8
Dependent Claim
33 words
A semiconductor laser device according to claim 6, wherein the refractive index of said optical guiding layer is between that of said active layer and that of said first and second cladding layers.
Claim 9
Dependent Claim
26 words
A semiconductor laser device according to claim 7, wherein said diffraction grating on said optical guiding layer comprises a corrugation having a periodicity of 2500 angstroms.
Claim 10
Dependent Claim
40 words
A semiconductor laser device according to claim 8, wherein said first cladding layer is formed on a semiconductor substrate, a cap layer is formed on said second cladding layer, and electrodes are formed on said cap layer and said substrate.
Claim 11
Dependent Claim
27 words
A semiconductor laser device according to claim 9, wherein said laser device is a distributed feedback semiconductor laser device or a distributed Bragg reflection semiconductor laser device.
Claim 12
Dependent Claim
92 words
A semiconductor laser device having an optical structure comprising: a GaAlAs first cladding layer, a non-doped GaAs active layer for laser oscillation formed on said first cladding layer, a GaAlAs buffer layer formed on said active layer an InGaPAs optical guiding layer having a diffraction grating thereon formed on said buffer layer, and a GaAlAs second cladding layer formed on said optical guiding layer, wherein the width of the forbidden band of said buffer layer is greater than that of said active layer and smaller than that of said optical guiding layer.
Claim 13
Dependent Claim
92 words
A semiconductor laser device having an optical structure comprising: a GaAlAs first cladding layer, a non-doped GaAs active layer for laser oscillation formed on said first cladding layer, a GaAlAs buffer layer formed on said active layer an InGaPAs optical guiding layer having a diffraction grating thereon formed on said buffer layer, and a GaAlAs second cladding layer formed on said optical guiding layer, wherein the width of the forbidden band of said buffer layer is greater than that of said active layer and smaller than that of said optical guiding layer.
Claim 14
Dependent Claim
68 words
A semiconductor laser device according to claim 11, wherein the forbidden band widths of said active layer, said buffer layer, said optical guiding layer, said first cladding layer, and second cladding layer are E 3 , E 9 , E 4 , E 2 , and E 5 , respectively, the following relationships therebetween are achieved: E.sub.3 <E.sub.9 <E.sub.4 <E.sub.2 & E.sub.5, and E.sub.2 &E.sub.5 -E.sub.3 ≧0.3 eV.
Claim 15
Dependent Claim
44 words
A semiconductor laser device according to claim 12, wherein said optical guiding layer comprises In 1-y Ga y P 1-z As z (0.68≦y≦1, 0.34≦z≦1, and z=2.04y-1.04), and wherein said first cladding layer and said second cladding layer comprise Ga 1-x Al x As (0.2≦x≦1).
Claim 16
Dependent Claim
33 words
A semiconductor laser device according to claim 13, wherein the refractive index of said optical guiding layer is between that of said active layer and that of said first and second cladding layers.
Claim 17
Dependent Claim
26 words
A semiconductor laser device according to claim 14, wherein said diffraction grating on said optical guiding layer comprises a corrugation having a periodicity of 2500 angstroms.
Claim 18
Dependent Claim
40 words
A semiconductor laser device according to claim 15, wherein said first cladding layer is formed on a semiconductor substrate, a cap layer is formed on said second cladding layer, and electrodes are formed on said cap layer and said substrate.
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) | 1991-05-17 | 1991-11-16 | 1992-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-17 | 1995-11-16 | 1996-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-17 | 1999-11-16 | 2000-05-17 | $7700.00 | Window Closed / Lapsed |