US4731792A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Semiconductor laser device with decreased light intensity noise
Assignee: Panasonic Holdings Corp
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Filing: 1986-12-30
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Granted: 1988-03-15
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Expires: 2006-12-30
Abstract
Abstract In a TRS (twin ridge substrate) type semiconductor laser, reflectivity at both facets of the resonator at the oscillation wavelength is selected to be higher than the reflectivity of the semiconductor crystal of the laser device, but smaller than 1, thereby stabilizing the light oscillation with a low S/N ratio.
Inventors
- 👤 Hirokazu Shimizu
- 👤 Masahiro Kume
- 👤 Masuru Wada
- 👤 Kunio Itoh
- 👤 Ken Hamada
- 👤 Fumiko Tajiri
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:24
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/02; H01S5/028; H01S5/0014; H01S5/06; H01S5/068; H01S5/0683; H01S5/20; H01S5/22; H01S5/223; H01S5/2232; H01S5/2234; H01S5/2235
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
35 words
In a semiconductor laser device, the improvement comprising: a resonator having light reflectivities of first and second predetermined values at each of two facets in a range of 0.45 to 0.8 for the oscillation wavelength.
Claim 2
Dependent Claim
35 words
In a semiconductor laser device, the improvement comprising: a resonator having light reflectivities of first and second predetermined values at each of two facets in a range of 0.45 to 0.8 for the oscillation wavelength.
Claim 3
Dependent Claim
33 words
An improvement in a semiconductor laser device in accordance with claim 1, wherein each of said facets of the resonator comprises at least one double layer of two substances having different refractive indexes.
Claim 4
Dependent Claim
56 words
In a semiconductor laser device, the improvement comprising: a resonator having light reflectivities of first and second predetermined values at each of two facets in a range of 0.45 to 0.8 for the oscillation wavelength, said facets being clad with a multi-layered coating having alternate repeated lamination of layers of two substances having different refractive indexes.
Claim 5
Dependent Claim
56 words
In a semiconductor laser device, the improvement comprising: a resonator having light reflectivities of first and second predetermined values at each of two facets in a range of 0.45 to 0.8 for the oscillation wavelength, said facets being clad with a multi-layered coating having alternate repeated lamination of layers of two substances having different refractive indexes.
Claim 6
Dependent Claim
72 words
In a semiconductor laser device, the improvement comprising: a semiconductor substrate on a principal face thereof two parallel ridges defining a stripe-shaped recess as a resonance cavity between said two parallel ridges; plural semiconductor layers including an active layer formed on said principal face; and two facets for said cavity which are formed vertical to said plural semiconductor layer, each facet having a predetermined reflectivity in a range of 0.45 to 0.8.
Claim 7
Dependent Claim
72 words
In a semiconductor laser device, the improvement comprising: a semiconductor substrate on a principal face thereof two parallel ridges defining a stripe-shaped recess as a resonance cavity between said two parallel ridges; plural semiconductor layers including an active layer formed on said principal face; and two facets for said cavity which are formed vertical to said plural semiconductor layer, each facet having a predetermined reflectivity in a range of 0.45 to 0.8.
Claim 8
Dependent Claim
49 words
An improvement in a semiconductor laser device in accordance with claim 4, further comprising means for detecting light output from each facet and feeding the light output back as a signal proportional to the output of the other facet so as to control operation current to stabilize light output.
Claim 9
Dependent Claim
93 words
A semiconductor laser device comprising: a semiconductor substrate having two parallel ridges on a principal face thereof defining a stripe-shaped recess as a resonance cavity between said two parallel ridges; plural semiconductor layers including an active layer formed on said principal face; two facets for said cavity which are formed vertical to said plural semiconductor layers, each facet having a predetermined reflectivity in a range of 0.45 to 0.8; coatings having alternate repeated lamination of layers of two substances having different refractive indexes formed on said facets for increasing reflectivity at said facets.
Claim 10
Dependent Claim
93 words
A semiconductor laser device comprising: a semiconductor substrate having two parallel ridges on a principal face thereof defining a stripe-shaped recess as a resonance cavity between said two parallel ridges; plural semiconductor layers including an active layer formed on said principal face; two facets for said cavity which are formed vertical to said plural semiconductor layers, each facet having a predetermined reflectivity in a range of 0.45 to 0.8; coatings having alternate repeated lamination of layers of two substances having different refractive indexes formed on said facets for increasing reflectivity at said facets.
Claim 11
Dependent Claim
71 words
In a semiconductor laser device, the improvement comprising: a resonator having light reflectivities of first and second predetermined values at each of two facets in a range of 0.45 to 0.8 for the oscillation wavelength; and means for detecting light output from each facet and feeding the light output back as a signal proportional to the output of the other facet so as to control operation current to stabilize light output.
Claim 12
Dependent Claim
71 words
In a semiconductor laser device, the improvement comprising: a resonator having light reflectivities of first and second predetermined values at each of two facets in a range of 0.45 to 0.8 for the oscillation wavelength; and means for detecting light output from each facet and feeding the light output back as a signal proportional to the output of the other facet so as to control operation current to stabilize light output.
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) | 1991-03-15 | 1991-09-14 | 1992-03-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-15 | 1995-09-14 | 1996-03-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-15 | 1999-09-14 | 2000-03-15 | $7700.00 | Window Closed / Lapsed |