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US5177758A
Expired / Lapsed
US
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Semiconductor laser device with plural active layers and changing optical properties
Assignee: Opnext Japan Inc
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Filing: 1991-12-06
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Granted: 1993-01-05
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Expires: 2011-12-06
Abstract
Abstract A wavelength-tunable semiconductor laser device presenting a large wavelength-tunable range or a very-high-speed modulating semiconductor laser device having a distributed feedback structure including a diffraction grating as in the case of a DBR laser or a DFB laser incorporates therein a plurality of active layers differing from one another in constituent elements or composition ratio or thickness for reducing spectral line widths, while improving single-mode spectral oscillation characteristics.
Inventors
- 👤 Akihiko Oka
- 👤 Shinji Sakano
- 👤 Naoki Chinone
- 👤 Tsukuru Ohtoshi
- 👤 Kazuhisa Uomi
- 👤 Tomonobu Tsuchiya
- 👤 Makoto Okai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:06
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/10; B; B82; B82Y; B82Y20/00; H01S5/06; H01S5/062; H01S5/0625; H01S5/06255; H01S5/06258; H01S5/12; H01S5/06209; H01S5/06213; H01S5/06256; H01S5/1028; H01S5/1053; H01S5/106; H01S5/20; H01S5/22; H01S5/227; H01S5/2275; H01S5/30; H01S5/34; H01S5/3428; H01S5/343; H01S5/34306; H01S5/34313; H01S5/3434
Claims Analysis
Total Claims: 47
Claim 1
Independent Claim
159 words
A semiconductor laser device, comprising: a plurality of semiconductor regions having active layers optically coupled to one another and susceptible to undergo changes in gain upon injection of carriers; said plurality of semiconductor regions including an amplification region having an optical amplification active layer for emitting light in response to the injection of the carriers, and a DBR regions having a gain active layer for guiding the light emitted by said optical amplification active layer and a distributed feedback structure for feeding back the light being guided; means for injecting the carriers into said plurality of semiconductor regions; and a resonator structure for amplifying the light of a specific wavelength of those emitted by said optical amplification active region by selective feedback through said feedback structure; wherein differential gain coefficient to the injected carrier density of said gain active layer is made different from the differential gain coefficient to the injected carrier density in said optical amplification active layer.
Claim 2
Dependent Claim
159 words
A semiconductor laser device, comprising: a plurality of semiconductor regions having active layers optically coupled to one another and susceptible to undergo changes in gain upon injection of carriers; said plurality of semiconductor regions including an amplification region having an optical amplification active layer for emitting light in response to the injection of the carriers, and a DBR regions having a gain active layer for guiding the light emitted by said optical amplification active layer and a distributed feedback structure for feeding back the light being guided; means for injecting the carriers into said plurality of semiconductor regions; and a resonator structure for amplifying the light of a specific wavelength of those emitted by said optical amplification active region by selective feedback through said feedback structure; wherein differential gain coefficient to the injected carrier density of said gain active layer is made different from the differential gain coefficient to the injected carrier density in said optical amplification active layer.
Claim 3
Dependent Claim
28 words
A semiconductor laser device according to claim 1, wherein a semiconductor material constituting said optical amplification layer is different from a semiconductor material constituting said gain active layer.
Claim 4
Dependent Claim
19 words
A semiconductor laser device according to claim 1, wherein said plurality of active layers have a quantum well structure.
Claim 5
Dependent Claim
28 words
A semiconductor laser device according to claim 1, wherein the differential gain coefficient of said gain active layer is smaller than that of said optical amplification active layer.
Claim 6
Dependent Claim
28 words
A semiconductor laser device according to claim 1 further comprising a phase control region including an optical waveguide layer for light propagation formed of an active semiconductor material.
Claim 7
Dependent Claim
25 words
A semiconductor laser device according to claim 5, wherein said phase control region includes an electrode for changing an optical path length of said resonator.
Claim 8
Dependent Claim
30 words
A semiconductor laser device according to claim 5, wherein said optical amplification active layer and said gain active layer are optically coupled directly or indirectly through said phase control region.
Claim 9
Dependent Claim
28 words
A semiconductor laser device according to claim 1 further comprising a phase control region including an optical waveguide layer for light propagation formed of a passive semiconductor material.
Claim 10
Dependent Claim
20 words
A semiconductor laser device according to claim 7, wherein said optical waveguide layer is formed of an active semiconductor material.
Claim 11
Dependent Claim
25 words
A semiconductor laser device according to claim 1, wherein said DBR region includes an electrode for changing the refractive index of said distributed feedback structure.
Claim 12
Dependent Claim
91 words
A semiconductor laser device, comprising: a plurality of semiconductor regions including a plurality of active layers coupled optically and having gains susceptible to change upon injection of carriers; means for injecting the carriers into said plurality of the active regions; and a resonator structure for amplifying and oscillating light of a specific wavelength differing from said gain peak wavelengths by selectively feeding back the light of said specific wavelength; wherein said plurality of the active layers compensate mutually for variations in the refractive index induced by variations in the carrier density.
Claim 13
Dependent Claim
91 words
A semiconductor laser device, comprising: a plurality of semiconductor regions including a plurality of active layers coupled optically and having gains susceptible to change upon injection of carriers; means for injecting the carriers into said plurality of the active regions; and a resonator structure for amplifying and oscillating light of a specific wavelength differing from said gain peak wavelengths by selectively feeding back the light of said specific wavelength; wherein said plurality of the active layers compensate mutually for variations in the refractive index induced by variations in the carrier density.
Claim 14
Dependent Claim
20 words
A semiconductor laser device according to claim 11, wherein said plurality of the active layers exhibit different gain peak wavelengths.
Claim 15
Dependent Claim
37 words
A semiconductor laser device according to claim 12, wherein said resonator structure amplifies through selective feedback the light having a wavelength differing from said plurality of the gain peak wavelengths as the light of said specific wavelength.
Claim 16
Dependent Claim
31 words
A semiconductor laser device according to claim 12, wherein said resonator structure feeds back selectively the light having as said specific wavelength a wavelength lying intermediate between said different peak wavelengths.
Claim 17
Dependent Claim
33 words
A semiconductor laser device according to claim 12, wherein said resonator structure feeds back the light having as said specific wavelength a wavelength other than those lying intermediate between said different peak wavelengths.
Claim 18
Dependent Claim
84 words
A semiconductor laser device, comprising: a plurality of active regions; means for injecting the carriers into said active regions; and a diffraction grating for feeding back light having a specific wavelength of those emitted from said active regions; wherein said diffraction grating is disposed in the vicinity of at least one of said plural active regions, and wherein said plural regions inclusive of said one region differ from one another in respect to change in the gain brought about by the injection of carriers.
Claim 19
Dependent Claim
84 words
A semiconductor laser device, comprising: a plurality of active regions; means for injecting the carriers into said active regions; and a diffraction grating for feeding back light having a specific wavelength of those emitted from said active regions; wherein said diffraction grating is disposed in the vicinity of at least one of said plural active regions, and wherein said plural regions inclusive of said one region differ from one another in respect to change in the gain brought about by the injection of carriers.
Claim 20
Dependent Claim
85 words
A semiconductor laser device, comprising: a plurality of active regions; means for injecting the carriers into said active regions; and a diffraction grating for feeding back light having a specific wavelength of those emitted from said active regions; wherein said diffraction grating is disposed in the vicinity of at least one of said plural active regions, and wherein said plural regions inclusive of said one region differ from one another in respect to change in the refractive index brought about by the injection of carriers.
Claim 21
Dependent Claim
85 words
A semiconductor laser device, comprising: a plurality of active regions; means for injecting the carriers into said active regions; and a diffraction grating for feeding back light having a specific wavelength of those emitted from said active regions; wherein said diffraction grating is disposed in the vicinity of at least one of said plural active regions, and wherein said plural regions inclusive of said one region differ from one another in respect to change in the refractive index brought about by the injection of carriers.
Claim 22
Dependent Claim
97 words
A semiconductor laser device, comprising: a plurality of active regions; means for injecting the carriers into said active regions; and a diffraction grating for feeding back light having a specific wavelength of those emitted from said active regions; wherein said diffraction grating is disposed in the vicinity of at least one of said plural active regions; and wherein said plural active layers are made different from one another in respect to magnitude of change in the gain for an amount of carriers injected to thereby suppress self-oscillation only in a specific one of said plural active layers.
Claim 23
Dependent Claim
97 words
A semiconductor laser device, comprising: a plurality of active regions; means for injecting the carriers into said active regions; and a diffraction grating for feeding back light having a specific wavelength of those emitted from said active regions; wherein said diffraction grating is disposed in the vicinity of at least one of said plural active regions; and wherein said plural active layers are made different from one another in respect to magnitude of change in the gain for an amount of carriers injected to thereby suppress self-oscillation only in a specific one of said plural active layers.
Claim 24
Dependent Claim
85 words
A semiconductor laser device, comprising: a plurality of active layers; means for injecting the carriers into said plural active layers; and a diffraction grating provided locally for oscillating light cf a specific wavelength of those emitted by said active layers; wherein at least one of said plural active layers is disposed in the vicinity of said diffraction grating, whereby said plural active layers are rendered to differ from one another in respect to magnitude of change in the refractive index for an amount of carriers
Claim 25
Dependent Claim
85 words
A semiconductor laser device, comprising: a plurality of active layers; means for injecting the carriers into said plural active layers; and a diffraction grating provided locally for oscillating light cf a specific wavelength of those emitted by said active layers; wherein at least one of said plural active layers is disposed in the vicinity of said diffraction grating, whereby said plural active layers are rendered to differ from one another in respect to magnitude of change in the refractive index for an amount of carriers
Claim 26
Dependent Claim
91 words
A semiconductor laser device, comprising: a plurality of active layers; means for injecting the carriers into said plural active layers; and a diffraction grating provided locally for oscillating light of a specific wavelength of those emitted by said active layers; wherein change of refractive index/change in gain brought about by carrier injection in the first active layer disposed in the vicinity of said diffractive index and/or in at least one of the second one or more active layers are greater than those in the other one(s) of said second active layers.
Claim 27
Dependent Claim
91 words
A semiconductor laser device, comprising: a plurality of active layers; means for injecting the carriers into said plural active layers; and a diffraction grating provided locally for oscillating light of a specific wavelength of those emitted by said active layers; wherein change of refractive index/change in gain brought about by carrier injection in the first active layer disposed in the vicinity of said diffractive index and/or in at least one of the second one or more active layers are greater than those in the other one(s) of said second active layers.
Claim 28
Dependent Claim
109 words
A semiconductor laser device, comprising: a plurality of active layers; means for injecting the carriers into said plural active layers; and a diffraction grating provided locally for oscillating light of a specific wavelength of those emitted by said active layers; wherein in the first active layer disposed in the vicinity of said diffractive grating and in the second one or more other active layer, either one or both of said first active layer and said second active layer are formed in a multi-layer structure, and wherein at least one of the active layers has a quantum well layer whose thickness is smaller than that of said second active layer.
Claim 29
Dependent Claim
109 words
A semiconductor laser device, comprising: a plurality of active layers; means for injecting the carriers into said plural active layers; and a diffraction grating provided locally for oscillating light of a specific wavelength of those emitted by said active layers; wherein in the first active layer disposed in the vicinity of said diffractive grating and in the second one or more other active layer, either one or both of said first active layer and said second active layer are formed in a multi-layer structure, and wherein at least one of the active layers has a quantum well layer whose thickness is smaller than that of said second active layer.
Claim 30
Dependent Claim
37 words
A semiconductor laser device according to claim 18, wherein said means for injecting the carriers are so provided as to be capable of injecting the carriers into said plurality of the active layers independent of one another.
Claim 31
Dependent Claim
24 words
A semiconductor laser device according to claim 18, including an optical waveguide for optically coupling said plurality of the active regions to one another.
Claim 32
Dependent Claim
51 words
A semiconductor laser device according to claim 18, wherein said active layer provided in the vicinity of said diffraction grating is disposed in parallel with said grating, and wherein oscillation wavelength is changed by changing an amount of carriers injected into said active layer provided in the vicinity of said grating.
Claim 33
Dependent Claim
72 words
A semiconductor laser device, comprising: a plurality of active layers; means for injecting carriers into said plural active layers; and a diffraction grating provided locally on a region through which light travels for oscillating light of a specific wavelength of those emitted by said active layers; wherein variations in refractive index brought about by variations in the amount of injected carriers in said plurality of the active regions are mutually compensated for.
Claim 34
Dependent Claim
72 words
A semiconductor laser device, comprising: a plurality of active layers; means for injecting carriers into said plural active layers; and a diffraction grating provided locally on a region through which light travels for oscillating light of a specific wavelength of those emitted by said active layers; wherein variations in refractive index brought about by variations in the amount of injected carriers in said plurality of the active regions are mutually compensated for.
Claim 35
Dependent Claim
71 words
A semiconductor laser device, comprising: a plurality of active layers; means for injecting carriers into said plural active layers; and a diffraction grating provided on an optical axis along which light travels for oscillating light of a specific wavelength of those emitted by said active layers; wherein changes in gain brought about by injection of carriers in said plurality of the active regions are different from one to another active regions.
Claim 36
Dependent Claim
71 words
A semiconductor laser device, comprising: a plurality of active layers; means for injecting carriers into said plural active layers; and a diffraction grating provided on an optical axis along which light travels for oscillating light of a specific wavelength of those emitted by said active layers; wherein changes in gain brought about by injection of carriers in said plurality of the active regions are different from one to another active regions.
Claim 37
Dependent Claim
26 words
A semiconductor laser device according to claim 25, wherein said plurality of the active layers are disposed in cascade in the direction in which light travels.
Claim 38
Dependent Claim
26 words
A semiconductor laser device according to claim 25, wherein said plurality of the active layers are disposed in parallel to the direction in which light travels.
Claim 39
Dependent Claim
24 words
A semiconductor laser device according to claim 25, wherein said plurality of the active layers have respective semiconductor crystal compositions differing from one another.
Claim 40
Dependent Claim
21 words
A semiconductor laser device according to claim 25, wherein at least one of said plural active layers has a quantum well.
Claim 41
Dependent Claim
21 words
A semiconductor laser device according to claim 25, wherein said plurality of the active layers have quantum wells of different thicknesses.
Claim 42
Dependent Claim
25 words
A semiconductor laser device according to claim 25, including electrodes for injecting the carriers into said plurality of the active layers independent of one another.
Claim 43
Dependent Claim
73 words
A semiconductor laser device, wherein the optical path length of light traveling through a passive semiconductor optical waveguide is changed by changing refractive index of said optical waveguide by injecting carriers thereto, and wherein an optical active layer is disposed in said optical waveguide in parallel with the direction in which light travels through said optical waveguide to thereby reduce absorption loss produced in said optical waveguide by the injection of the carriers.
Claim 44
Dependent Claim
73 words
A semiconductor laser device, wherein the optical path length of light traveling through a passive semiconductor optical waveguide is changed by changing refractive index of said optical waveguide by injecting carriers thereto, and wherein an optical active layer is disposed in said optical waveguide in parallel with the direction in which light travels through said optical waveguide to thereby reduce absorption loss produced in said optical waveguide by the injection of the carriers.
Claim 45
Dependent Claim
19 words
A semiconductor laser device according to claim 33, wherein gain of said optical waveguide is 30 cm -1 .
Claim 46
Dependent Claim
63 words
A semiconductor laser device according to claim 33, wherein the layer thickness of the active material exhibiting maximum gain at the wavelength of light guided through said optical waveguide is not greater than 1/15 of the wavelength for use, and wherein the thickness of the passive guide layer giving rise to absorption loss is not smaller than 1/15 of the wavelength for use.
Claim 47
Dependent Claim
28 words
A semiconductor laser device according to claim 33, wherein the wavelength at which said optical active layer exhibits a maximum gain is shorter than that of light guided.
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) | 1996-01-05 | 1996-07-06 | 1997-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-01-05 | 2000-07-06 | 2001-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-01-05 | 2004-07-06 | 2005-01-05 | $7700.00 | Window Closed / Lapsed |