EP0254568A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A semiconductor laser device
Assignee: Mitsubishi Electric Corp
•
Filing: 1987-07-23
•
Granted: —
•
Expires: 2007-07-23
Abstract
Abstract A semiconductor laser having an active layer (104) of quantum well structure, where the resonator loss is enhanced thereby to conduct an oscillation at a high quantum level.
Inventors
- 👤 Yasunori C/O Mitsubishi Denki K.K. Tokuda
- 👤 Kenzo C/O Mitsubishi Denki K.K. Fujiwara
- 👤 Noriaki C/O Mitsubishi Denki K.K. Tsukada
- 👤 Keisuke C/O Mitsubishi Denki K.K. Kojima
- 👤 Yoshinori C/O Mitsubishi Denki K.K. Nomura
- 👤 Teruhito C/O Mitsubishi Denki K.K. Matsui
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 05:25
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/06; H01S5/0601; B; B82; B82Y; B82Y20/00; H01S5/062; H01S5/06209; H01S5/0622; H01S5/10; H01S5/12; H01S5/30; H01S5/34; H01S5/40; H01S5/4025; H01S5/4031; H01S5/02; H01S5/028; H01S5/0602; H01S5/06203; H01S5/06206; H01S5/06213; H01S5/0625; H01S5/06255; H01S5/06258; H01S5/1039; H01S5/1206; H01S5/1215; H01S5/1228; H01S5/125; H01S5/20; H01S5/2004; H01S5/2009; H01S5/32; H01S5/3211; H01S5/3216; H01S5/3409; H01S5/3418; H01S5/4087; H01S5/50
Claims Analysis
Total Claims: 72
Claim 1
Independent Claim
27 words
A semiconductor laser having an active layer of quantum well structure, where the resonator loss is enhanced thereby to conduct an oscillation at a high quantum level.
Claim 2
Dependent Claim
27 words
A semiconductor laser having an active layer of quantum well structure, where the resonator loss is enhanced thereby to conduct an oscillation at a high quantum level.
Claim 3
Dependent Claim
26 words
A laser as defined in Claim 1, wherein said resonator loss in enchanced by providing a region having a large light absorption of the light waveguide.
Claim 4
Dependent Claim
34 words
A laser as defined in Claim 2, wherein said region having a large light absorption is a region to which a current is not injected, which is provided at a portion of said resonator.
Claim 5
Dependent Claim
27 words
A laser as defined in Claim 3, wherein said current non-injection region is produced by providing a portion having no electrode at said portion of said resonator.
Claim 6
Dependent Claim
29 words
A laser as defined in Claim 3 or 4, wherein said current non-injection region is produced by increasing the resistance of said portion of said resonator by proton irradiation.
Claim 7
Dependent Claim
30 words
A semiconductor laser having an active layer of quantum well structure, where the resonator internal loss is enhanced thereby to conduct oscillations of wavelengths corresponding more than two quantum levels.
Claim 8
Dependent Claim
30 words
A semiconductor laser having an active layer of quantum well structure, where the resonator internal loss is enhanced thereby to conduct oscillations of wavelengths corresponding more than two quantum levels.
Claim 9
Dependent Claim
61 words
A semiconductor laser having an active layer of quantum well structure, wherein a light absorption region is provided at the outside of the lightguide path of said active layer, the resonator internal loss is increased by said light absorption region, and the oscillation wavelength is controlled by the relationship between said resonator internal loss and the gain by an injection current.
Claim 10
Dependent Claim
61 words
A semiconductor laser having an active layer of quantum well structure, wherein a light absorption region is provided at the outside of the lightguide path of said active layer, the resonator internal loss is increased by said light absorption region, and the oscillation wavelength is controlled by the relationship between said resonator internal loss and the gain by an injection current.
Claim 11
Dependent Claim
24 words
A laser as defined in Claim 7, wherein the resonator internal loss due to said external light absorption region is increased by proton irradiation.
Claim 12
Dependent Claim
50 words
A laser as defined in Claim 7 or 8, wherein the resonator internal loss due to said external light absorption region is increased by conducting diffusion to said external light absorption region thereby to increase the carrier density thereof than that of said light waveguide portion of said active layer.
Claim 13
Dependent Claim
35 words
A laser as defined in any of Claims 7 to 9, wherein the light absorption quantity due to said external light absorption region is increased so as to enable oscillation at a particular quantum level.
Claim 14
Dependent Claim
45 words
A laser as defined in any of Claims 7 to 9, wherein the light absorption quantity of said external light absorption region is set so as to enable oscillations at a plurality of wavelengths at a plurality of quantum levels by changing said injection current.
Claim 15
Dependent Claim
40 words
A semiconductor laser which, having an active layer of quantum well structure, conducts oscillations at wavelengths corresponding to more than two quantum levels with enhancing the resonator internal loss, where the oscillation wavelengths are switched by changing the injection current.
Claim 16
Dependent Claim
40 words
A semiconductor laser which, having an active layer of quantum well structure, conducts oscillations at wavelengths corresponding to more than two quantum levels with enhancing the resonator internal loss, where the oscillation wavelengths are switched by changing the injection current.
Claim 17
Dependent Claim
49 words
A semiconductor laser which, having an active layer of quantum well structure, conducts oscillations at wavelengths corresponding to more than two quantum levels with increasing the resonator internal loss, where laser oscillations of more than two wavelengths are conducted at the same time by giving a predetermined injection current.
Claim 18
Dependent Claim
49 words
A semiconductor laser which, having an active layer of quantum well structure, conducts oscillations at wavelengths corresponding to more than two quantum levels with increasing the resonator internal loss, where laser oscillations of more than two wavelengths are conducted at the same time by giving a predetermined injection current.
Claim 19
Dependent Claim
37 words
A semiconductor laser having an active layer of quantum well structure and a means for changing the resonator internal loss in accordance with an external electric signal, where oscillations are enabled at a variety of quantum levels.
Claim 20
Dependent Claim
37 words
A semiconductor laser having an active layer of quantum well structure and a means for changing the resonator internal loss in accordance with an external electric signal, where oscillations are enabled at a variety of quantum levels.
Claim 21
Dependent Claim
58 words
A laser as defined in Claim 14, wherein said means for changing the resonator internal loss in accordance with said external electric signal utilizes the wavelength shift of the exciton absorption spectrum which occurs when a reverse bias is applied to a portion of the same layer structure as the layer structure to which a current is injected.
Claim 22
Dependent Claim
43 words
A semiconductor laser having an active layer of quantum well structure, where there are provided a plural number of injection electrodes and oscillations at a variety of quantum levels are enabled by controlling the injection current levels into the respective injection electrodes independently.
Claim 23
Dependent Claim
43 words
A semiconductor laser having an active layer of quantum well structure, where there are provided a plural number of injection electrodes and oscillations at a variety of quantum levels are enabled by controlling the injection current levels into the respective injection electrodes independently.
Claim 24
Dependent Claim
42 words
A laser as defined in Claim 16, wherein one of said divided electrodes is used to supply a current for laser oscillation and the other thereof is used to supply a current to an absorption region which is provided inside said resonator.
Claim 25
Dependent Claim
30 words
A semiconductor laser having an active layer of quantum well structure, where the mirror loss is enhanced and oscillations of wavelengths corresponding to more than two quantum levels are conducted.
Claim 26
Dependent Claim
30 words
A semiconductor laser having an active layer of quantum well structure, where the mirror loss is enhanced and oscillations of wavelengths corresponding to more than two quantum levels are conducted.
Claim 27
Dependent Claim
38 words
A semiconductor laser having an active layer of quantum well structure, where there is provided a laser resonator structure which selectively reflects only wavelengths corresponding to quantum levels higher than the lowest quantum level of (a) quantum well(s).
Claim 28
Dependent Claim
38 words
A semiconductor laser having an active layer of quantum well structure, where there is provided a laser resonator structure which selectively reflects only wavelengths corresponding to quantum levels higher than the lowest quantum level of (a) quantum well(s).
Claim 29
Dependent Claim
63 words
A laser as defined in Claim 19, wherein said laser resonator structure has a coating of reflection film which has a low reflectivity against the light of wavelength corresponding to the minimum quantum level and has a high reflectivity against the light of wavelength corresponding to said higher quantum level, which coating is provided at least at one of the laser end facet.
Claim 30
Dependent Claim
38 words
A laser as defined in Claim 19, wherein said laser resonator structure has a grating for reflecting the light of wavelength corresponding to said higher quantum level, which is provided at the inside or outside of the resonator.
Claim 31
Dependent Claim
60 words
A laser as defined in Claim 21, wherein there are provided a plurality of grating having different periods inside said resonator, current injections are conducted independently to said plurality of grating, and at least one of said plurality of grating is one for selectively reflecting the light of wavelength corresponding to a higher quantum level than the lowest quantum level.
Claim 32
Dependent Claim
39 words
A semiconductor laser which, having an active layer of quantum well structure, conducts oscillations of wavelengths corresponding to more than two quantum levels with enhancing the mirror loss, where the oscillation wavelengths are switched by changing an injection current.
Claim 33
Dependent Claim
39 words
A semiconductor laser which, having an active layer of quantum well structure, conducts oscillations of wavelengths corresponding to more than two quantum levels with enhancing the mirror loss, where the oscillation wavelengths are switched by changing an injection current.
Claim 34
Dependent Claim
47 words
A semiconductor laser which, having an active layer of quantum well structure, conducts oscillations of wavelengths corresponding to more than two quantum levels with enhancing the mirror loss, where more than two wavelength laser oscillations are conducted at the same time by giving a predetermined injection current.
Claim 35
Dependent Claim
47 words
A semiconductor laser which, having an active layer of quantum well structure, conducts oscillations of wavelengths corresponding to more than two quantum levels with enhancing the mirror loss, where more than two wavelength laser oscillations are conducted at the same time by giving a predetermined injection current.
Claim 36
Dependent Claim
60 words
A semiconductor laser having an active layer of quantum well structure, wherein there is provided a superlattice layer having an energy level which is equal to at least one of the plurality of quantum levels of the quantum well structure, and transitions of electrons between the superlattice layer and the quantum well active layer by the resonance tunneling effect occur.
Claim 37
Dependent Claim
60 words
A semiconductor laser having an active layer of quantum well structure, wherein there is provided a superlattice layer having an energy level which is equal to at least one of the plurality of quantum levels of the quantum well structure, and transitions of electrons between the superlattice layer and the quantum well active layer by the resonance tunneling effect occur.
Claim 38
Dependent Claim
61 words
A laser as defined in Claim 25, wherein a laser oscillation at a higher quantum level (n > 2) is enabled with supressing the laser oscillation at the lowest quantum level with the electrons at the lowest quantum level of said quantum well active layer being taken out from said active layer to said superlattice layer by a resonance tunneling effect.
Claim 39
Dependent Claim
57 words
An integrated semiconductor laser including a plurality of semiconductor lasers having the same resonator length on a same substrate, wherein the respective lasers have an active layer of quantum well structure having such a narrow width barrier layer that the electron of adjacent quantum wells are combined with each other and carrier injection regions of different sizes.
Claim 40
Dependent Claim
57 words
An integrated semiconductor laser including a plurality of semiconductor lasers having the same resonator length on a same substrate, wherein the respective lasers have an active layer of quantum well structure having such a narrow width barrier layer that the electron of adjacent quantum wells are combined with each other and carrier injection regions of different sizes.
Claim 41
Dependent Claim
38 words
A semiconductor laser array including a plurality of semiconductor lasers having quantum well structure active layers arranged in a transverse direction on a substrate, wherein the resonator internal loss of said semiconductor lasers are different from each other.
Claim 42
Dependent Claim
38 words
A semiconductor laser array including a plurality of semiconductor lasers having quantum well structure active layers arranged in a transverse direction on a substrate, wherein the resonator internal loss of said semiconductor lasers are different from each other.
Claim 43
Dependent Claim
29 words
An array as defined in Claim 28, wherein the resonator internal losses of said semiconductor lasers are differentiated by varing the stripe widths of the respective light waveguide paths.
Claim 44
Dependent Claim
41 words
A semiconductor laser array including a plurality of semiconductor lasers having a quantum well structure active layer arranged in a transverse direction, wherein the mirror losses due to the end surface reflectivity of said semiconductor lasers are different from each other.
Claim 45
Dependent Claim
41 words
A semiconductor laser array including a plurality of semiconductor lasers having a quantum well structure active layer arranged in a transverse direction, wherein the mirror losses due to the end surface reflectivity of said semiconductor lasers are different from each other.
Claim 46
Dependent Claim
21 words
A laser or array as defined in any preceding claim, wherein said active layer is of a single quantum well layer.
Claim 47
Dependent Claim
24 words
A laser or array as claimed in any of claims 1 to 30, wherein said active layer is of a multiple quantum well structure.
Claim 48
Dependent Claim
21 words
An array as defined in Claim 32, wherein said quantum well structures have different quantum well thicknesses and different material compositions.
Claim 49
Dependent Claim
25 words
An array as defined in Claim 32 or 33, wherein said quantum well structures have different thicknesses and different material compositions of said barrier layers.
Claim 50
Dependent Claim
26 words
A laser or array as defined in any preceding claim, wherein said semiconductor laser has the cladding layers having composition proportions varying in its thickness direction.
Claim 51
Dependent Claim
25 words
A laser or array as defined in any preceding claim, wherein said semiconductor laser conducts a light confinement in the transverse direction by impurity diffusion.
Claim 52
Dependent Claim
27 words
A laser or array as defined in any preceding claim, wherein said semiconductor laser conducts a light confinement in the transverse direction by a ridge waveguide structure.
Claim 53
Dependent Claim
26 words
A laser or array as defined in any preceding claim, wherein said semiconductor laser conducts a light confinement in the transverse direction by a buried heterostructure.
Claim 54
Dependent Claim
24 words
A laser or array as defined in any preceding claim, wherein said semiconductor laser conducts a light confinement in the transverse direction by CSP.
Claim 55
Dependent Claim
63 words
A laser or array as defined in any preceding claim, which includes a first conductivity type cladding layer, an active layer, a second conductivity type cladding layer, provided at the side of said active and cladding layer put between a pair of electrodes, wherein the width of said active layer is less than 10 micron, and the structure has a large internal loss.
Claim 56
Dependent Claim
29 words
A laser or array as defined in Claim 40, wherein the width of said active layer is less than 6 micron, and the structure has a large internal loss.
Claim 57
Dependent Claim
27 words
A laser or array as defined in Claim 40 or 41, wherein there is provided a optical confinement layer between said cladding layer and said active layer.
Claim 58
Dependent Claim
35 words
A laser or array as defined in any of Claims 40 to 42, wherein non-periodic concavo-convex is produced at the boundary between said active layer and said transverse confinement layer, thereby increasing the internal loss.
Claim 59
Dependent Claim
34 words
A laser or array as defined in any of Claims 40 to 43, wherein the width of said active layer is varied in the direction of waveguiding the light, thereby increasing the internal loss.
Claim 60
Dependent Claim
40 words
A laser or array as defined in any of Claims 40 to 44, wherein the boundary between said active and said transverse direction confinement layer is made not substantially vertical with the resonator end facet, thereby increasing the internal loss.
Claim 61
Dependent Claim
30 words
A laser or array as defined in any of Claims 40 to 45, wherein the width of said active layer is less than 1.5 microns, thereby increasing the internal loss.
Claim 62
Dependent Claim
25 words
A laser or array as defined in any of Claims 40 to 46, wherein the thickness of said active layer is less than 300 Angstroms.
Claim 63
Dependent Claim
106 words
A laser or array as defined in any preceding claim, which includes a first conductivity type cladding layer, an active layer, and a second conductivity type cladding layer put between a pair of electrodes, provided at the confronting side portions of said active layer and cladding layers, where said active layer is a quantum well layer in a separate confinement heterostructure provided with light guide layer having an intermediate energy band gap between said cladding layer and upper or lower surface of said active layer, and the width of said lightguide layer is less than 6 micron and the internal loss of light transmission is increased.
Claim 64
Dependent Claim
53 words
A laser or array as defined in Claim 48, wherein said lightguide layer has an intermediate energy band gap between said cladding layer and said quantum well active layer, and said energy band gap is increasing inclinedly or stepwisely as it becomes far from active layer in a direction vertical with said layer.
Claim 65
Dependent Claim
73 words
A laser or array as defined in Claim 48 or 49, wherein said lightguide layer has an energy band gap of inclined type or stepwise type in its portion or in its entirety, and the structure of that portion is in a superlattice structure comprising a quantum well layer comprising a first semiconductor and a barrier layer comprising a second semiconductor having an energy band gap larger than that of the first semiconductor.
Claim 66
Dependent Claim
52 words
A laser or array as defined in Claim 50, wherein said superlattice structure of said lightguide layer has a constant thickness of said barrier layer comprising a second semiconductor, and as it becomes far from said active layer as thinner the thickness of said quantum well layer comprising said first semiconductor becomes.
Claim 67
Dependent Claim
35 words
A laser or array as defined in any of Claims 48 to 51, wherein the absorption loss of said lightguide layer due to carriers is increased by doping donors or acceptors at a high concentration.
Claim 68
Dependent Claim
41 words
A laser or array as defined in any preceding claim, which has an active layer of quantum well structure, wherein said active layer is constituted by providing a plurality of quantum wells having different quantum energy levels close to each other.
Claim 69
Dependent Claim
28 words
A laser or array as defined in Claim 53, wherein said plurality of quantum wells having different quantum energy levels comprise same composition material and have different thicknesses.
Claim 70
Dependent Claim
28 words
A laser or array as defined in Claim 53, wherein said plurality of quantum wells having different quantum energy levels has the same thicknesses and different composition material.
Claim 71
Dependent Claim
27 words
A laser or array as defined in Claim 53, wherein said plurality of quantum wells having different quantum energy levels have different thicknesses and different composition material.
Claim 72
Dependent Claim
44 words
A laser or array as defined in any of Claims 53 to 56, wherein oscillations of a plurality of wavelengths corresponding to the respective quantum energy levels of the plurality of quantum wells are conducted by changing the injection current into said active layer.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.