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US5425041A Expired / Lapsed US ⏱️ 0.0 years remaining

Multiquantum barrier laser having high electron and hole reflectivity of layers

Assignee: Fujifilm Business Innovation Corp
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Filing: 1994-03-17
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Granted: 1995-06-13
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Expires: 2014-03-17
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Abstract

Abstract It is an object of the present invention to provide a highly efficient semiconductor laser unit having excellent temperature characteristics, in which electrons or holes are suppressed from overflowing from the active layer to the cladding layers while the threshold of current density is maintained low. The present invention is to provide a semiconductor laser unit fundamentally composed of an active layer and cladding layers in which the active layer is interposed between the cladding layers the semiconductor laser unit comprising: a multiquantum barrier layer including well layers and barrier layers disposed between the active layer and the cladding layers or disposed in the cladding layers close to the active layer, wherein the well and barrier layers have a high reflectivity with respect to the electrons and holes at a position close to Γ-point in the reciprocal lattice space, and also the well and barrier layers have a high reflectivity with respect to the electrons and holes at a position close to at least one of the primary symmetrical points.

Inventors

  • 👤 Yasuji Seko
  • 👤 Kiichi Ueyanagi
  • 👤 Yasuhiro Shiraki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 16:49
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/20; B; B82; B82Y; B82Y20/00; H01S5/2004; H01S5/2009; H01S5/2013; H01S5/30; H01S5/34; H01S5/343; H01S5/34326

Claims Analysis

Total Claims: 33
Claim 1
Independent Claim 145 words
A semiconductor laser unit having an active layer and cladding layers, wherein said active layer is interposed between said cladding layers, comprising: a multiquantum barrier layer including well layers and barrier layers disposed in one or both of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said well and barrier layers include at least one first pair of a well layer and a barrier layer and at least one second pair of a well layer and a barrier layer, said first pair of well and barrier layers having different characteristics from said second pair of well and barrier layers to provide relatively high reflectivities with respect to electrons and/or holes at a position close to a Γ-point in a reciprocal lattice space and at a position close to any one of primary symmetrical points.
Claim 2
Dependent Claim 145 words
A semiconductor laser unit having an active layer and cladding layers, wherein said active layer is interposed between said cladding layers, comprising: a multiquantum barrier layer including well layers and barrier layers disposed in one or both of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said well and barrier layers include at least one first pair of a well layer and a barrier layer and at least one second pair of a well layer and a barrier layer, said first pair of well and barrier layers having different characteristics from said second pair of well and barrier layers to provide relatively high reflectivities with respect to electrons and/or holes at a position close to a Γ-point in a reciprocal lattice space and at a position close to any one of primary symmetrical points.
Claim 3
Dependent Claim 23 words
The semiconductor laser unit according to claim 1, wherein said multiquantum barrier layer is composed of laminated multiquantum barrier layers of different characteristics.
Claim 4
Dependent Claim 19 words
The semiconductor laser unit according to claim 1, wherein said multiquantum barrier layer is made of AlGaInP system material.
Claim 5
Dependent Claim 29 words
The semiconductor laser unit according to claim 3, wherein said multiquantum barrier layer is composed of the lamination of a pair of GaInP well layer and AlInP barrier layer.
Claim 6
Dependent Claim 67 words
The semiconductor laser unit according to claim 4, wherein said multiquantum barrier layer is composed of a first, a second and a third laminated layers, and wherein 10 atomic well and barrier layers are alternately laminated in said first layer, 6 atomic well and barrier layers are alternately laminated in said second layer, and 4 atomic well and barrier layers are alternately laminated in said third layer.
Claim 7
Dependent Claim 91 words
The semiconductor laser unit according to claim 4, wherein said multiquantum barrier layer is composed of a first, a second and a third laminated layers, and wherein well and barrier layers, the thickness of which is respectively 25 to 35 Å, are alternately laminated in said first layer, well and barrier layers, the thickness of which is respectively 15 to 25 Å, are alternately laminated in said second layer, and well and barrier layers, the thickness of which is respectively 10 to 15 Å, are alternately laminated in said third layer.
Claim 8
Dependent Claim 136 words
A semiconductor laser unit, comprising: an active layer; cladding layers between which said active layer is interposed; and a multiquantum barrier layer disposed between said active layer and one of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said multiquantum barrier layer includes at least one first pair of a well layer and a barrier layer and at least one second pair of a well layer and a barrier layer, said first pair of well and barrier layers having different characteristics from said second pair of well and barrier layers to provide relatively high reflectivities with respect to electrons and/or holes at a plurality of primary symmetrical points in a reciprocal lattice space, or at respective positions close to the plurality of primary symmetrical points.
Claim 9
Dependent Claim 136 words
A semiconductor laser unit, comprising: an active layer; cladding layers between which said active layer is interposed; and a multiquantum barrier layer disposed between said active layer and one of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said multiquantum barrier layer includes at least one first pair of a well layer and a barrier layer and at least one second pair of a well layer and a barrier layer, said first pair of well and barrier layers having different characteristics from said second pair of well and barrier layers to provide relatively high reflectivities with respect to electrons and/or holes at a plurality of primary symmetrical points in a reciprocal lattice space, or at respective positions close to the plurality of primary symmetrical points.
Claim 10
Dependent Claim 23 words
The semiconductor laser unit according to claim 7, wherein said multiquantum barrier layer is composed of laminated multiquantum barrier layers of different characteristics.
Claim 11
Dependent Claim 19 words
The semiconductor laser unit according to claim 7, wherein said multiquantum barrier layer is made of AlGaInP system material.
Claim 12
Dependent Claim 29 words
The semiconductor laser unit according to claim 9, wherein said multiquantum barrier layer is composed of the lamination of a pair of GaInP well layer and AlInP barrier layer.
Claim 13
Dependent Claim 67 words
The semiconductor laser unit according to claim 10, wherein said multiquantum barrier layer is composed of a first, a second and a third laminated layers, and wherein 10 atomic well and barrier layers are alternately laminated in said first layer, 6 atomic well and barrier layers are alternately laminated in said second layer, and 4 atomic well and barrier layers are alternately laminated in said third layer.
Claim 14
Dependent Claim 91 words
The semiconductor laser unit according to claim 10, wherein said multiquantum barrier layer is composed of a first, a second and a third laminated layers, and wherein well and barrier layers, the thickness of which is respectively 25 to 35 Å, are alternately laminated in said first layer, well and barrier layers, the thickness of which is respectively 15 to 25 Å, are alternately laminated in said second layer, and well and barrier layers, the thickness of which is respectively 10 to 15 Å, are alternately laminated in said third layer.
Claim 15
Dependent Claim 159 words
A semiconductor laser unit, comprising: an active layer; cladding layers between which said active layer is interposed; and a multiquantum barrier disposed between said active layer and one of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said multiquantum barrier layer includes at least one first pair of a well layer and a barrier layer and at least one second pair of a well layer and a barrier layer, said first pair of well and barrier layers having different characteristics from said second pair of well and barrier layers to provide relatively high reflectivities with respect to electrons and/or holes at a Γ-point in a reciprocal lattice space or at a position close to said Γ-point in the reciprocal lattice space and at at least one of primary symmetrical points in the reciprocal lattice space except said Γ-point, or at a point close to the primary symmetrical point.
Claim 16
Dependent Claim 159 words
A semiconductor laser unit, comprising: an active layer; cladding layers between which said active layer is interposed; and a multiquantum barrier disposed between said active layer and one of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said multiquantum barrier layer includes at least one first pair of a well layer and a barrier layer and at least one second pair of a well layer and a barrier layer, said first pair of well and barrier layers having different characteristics from said second pair of well and barrier layers to provide relatively high reflectivities with respect to electrons and/or holes at a Γ-point in a reciprocal lattice space or at a position close to said Γ-point in the reciprocal lattice space and at at least one of primary symmetrical points in the reciprocal lattice space except said Γ-point, or at a point close to the primary symmetrical point.
Claim 17
Dependent Claim 23 words
The semiconductor laser unit according to claim 13, wherein said multiquantum barrier layer is composed of laminated multiquantum barrier layers of different characteristics.
Claim 18
Dependent Claim 19 words
The semiconductor laser unit according to claim 13, wherein said multiquantum barrier layer is made of AlGaInP system material.
Claim 19
Dependent Claim 29 words
The semiconductor laser unit according to claim 15, wherein said multiquantum barrier layer is composed of the lamination of a pair of GaInP well layer and AlInP barrier layer.
Claim 20
Dependent Claim 65 words
The semiconductor laser unit according to claim 16, wherein said multiquantum barrier layer is composed of the first, second and third laminated layers, and wherein 10 atomic well and barrier layers are alternately laminated in said first layer, 6 atomic well and barrier layers are alternately laminated in said second layer, and 4 atomic well and barrier layers are alternately laminated in said third layer.
Claim 21
Dependent Claim 89 words
The semiconductor laser unit according to claim 16, wherein said multiquantum barrier layer is composed of the first, second and third laminated layers, and wherein well and barrier layers, the thickness of which is respectively 25 to 35 Å, are alternately laminated in said first layer, well and barrier layers, the thickness of which is respectively 15 to 25 Å, are alternately laminated in said second layer, and well and barrier layers, the thickness of which is respectively 10 to 15 Å, are alternately laminated in said third layer.
Claim 22
Dependent Claim 147 words
A semiconductor laser unit having an active layer and cladding layers, wherein said active layer is interposed between said cladding layers, comprising: laminated multiquantum barrier layers of different characteristics and of the AlGaInP material system and including a lamination of a pair of a GaInP well layer and an AlInP barrier layer, said laminated multiquantum barrier layers including well layers and barrier layers disposed between said active layer and one of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said well and barrier layers have relatively high reflectivities with respect to electrons and/or holes at a position close to a Γ-point in a reciprocal lattice space, and said well and barrier layers have a high reflectivity with respect to the electrons and holes at a position close to at least one of the primary symmetrical points.
Claim 23
Dependent Claim 147 words
A semiconductor laser unit having an active layer and cladding layers, wherein said active layer is interposed between said cladding layers, comprising: laminated multiquantum barrier layers of different characteristics and of the AlGaInP material system and including a lamination of a pair of a GaInP well layer and an AlInP barrier layer, said laminated multiquantum barrier layers including well layers and barrier layers disposed between said active layer and one of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said well and barrier layers have relatively high reflectivities with respect to electrons and/or holes at a position close to a Γ-point in a reciprocal lattice space, and said well and barrier layers have a high reflectivity with respect to the electrons and holes at a position close to at least one of the primary symmetrical points.
Claim 24
Dependent Claim 66 words
The semiconductor laser unit according to claim 19, wherein one said laminated multiquantum barrier layer is composed of first, second, and third laminated layers, and wherein 10 atomic well and barrier layers are alternately laminated in said first layer, 6 atomic well and barrier layers are alternately laminated in said second layer, and 4 atomic well and barrier layers are alternately laminated in said third layer.
Claim 25
Dependent Claim 90 words
The semiconductor laser unit according to claim 19, wherein one said laminated multiquantum barrier layer is composed of first, second, and third laminated layers, and wherein well and barrier layers, the thickness of which is respectively 25 to 35 Å, are alternately laminated in said first layer, well and barrier layers, the thickness of which is respectively 15 to 25 Å, are alternately laminated in said second layer, and well and barrier layers, the thickness of which is respectively 10 to 15 Å, are alternately laminated in said third layer.
Claim 26
Dependent Claim 119 words
A semiconductor laser unit, comprising: an active layer; cladding layers between which said active layer is interposed; and laminated multiquantum barrier layers of different characteristics and of the AlGaInP material system and including a lamination of a pair of a GaInP well layer and an AlInP barrier layer, said laminated multiquantum barrier layers disposed between said active layer and one of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said laminated multiquantum barrier layers have relatively high reflectivities with respect to electrons and/or holes at a plurality of primary symmetrical points in a reciprocal lattice space, or at respective positions close to the plurality of primary symmetrical points.
Claim 27
Dependent Claim 119 words
A semiconductor laser unit, comprising: an active layer; cladding layers between which said active layer is interposed; and laminated multiquantum barrier layers of different characteristics and of the AlGaInP material system and including a lamination of a pair of a GaInP well layer and an AlInP barrier layer, said laminated multiquantum barrier layers disposed between said active layer and one of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said laminated multiquantum barrier layers have relatively high reflectivities with respect to electrons and/or holes at a plurality of primary symmetrical points in a reciprocal lattice space, or at respective positions close to the plurality of primary symmetrical points.
Claim 28
Dependent Claim 65 words
The semiconductor laser unit according to claim 22, wherein one said multiquantum barrier layer is composed of first, second, and third laminated layers, and wherein 10 atomic well and barrier layers are alternately laminated in said first layer, 6 atomic well and barrier layers are alternately laminated in said second layer, and 4 atomic well and barrier layers are alternately laminated in said third layer.
Claim 29
Dependent Claim 89 words
The semiconductor laser unit according to claim 22, wherein one said multiquantum barrier layer is composed of first, second, and third laminated layers, and wherein well and barrier layers, the thickness of which is respectively 25 to 35 Å, are alternately laminated in said first layer, well and barrier layers, the thickness of which is respectively 15 to 25 Å, are alternately laminated in said second layer, and well and barrier layers, the thickness of which is respectively 10 to 15 Å, are alternately laminated in said third layer.
Claim 30
Dependent Claim 143 words
A semiconductor laser unit, comprising: an active layer; cladding layers between which said active layer is interposed; and laminated multiquantum barrier layers of different characteristics and of the AlGaInP material system and including a lamination of a pair of a GaInP well layer and an AlInP barrier layer, said laminated multiquantum barrier layers disposed between said active layer and one of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said laminated multiquantum barrier layers having relatively high reflectivities with respect to electrons and/or holes at a Γ-point in a reciprocal lattice space or at a position close to said Γ-point in the reciprocal lattice space and at at least one of primary symmetrical points in the reciprocal lattice space except said Γ-point, or at a point close to the primary symmetrical point.
Claim 31
Dependent Claim 143 words
A semiconductor laser unit, comprising: an active layer; cladding layers between which said active layer is interposed; and laminated multiquantum barrier layers of different characteristics and of the AlGaInP material system and including a lamination of a pair of a GaInP well layer and an AlInP barrier layer, said laminated multiquantum barrier layers disposed between said active layer and one of said cladding layers, or disposed in one or both of said cladding layers close to said active layer, wherein said laminated multiquantum barrier layers having relatively high reflectivities with respect to electrons and/or holes at a Γ-point in a reciprocal lattice space or at a position close to said Γ-point in the reciprocal lattice space and at at least one of primary symmetrical points in the reciprocal lattice space except said Γ-point, or at a point close to the primary symmetrical point.
Claim 32
Dependent Claim 65 words
The semiconductor laser unit according to claim 25, wherein one said multiquantum barrier layer is composed of first, second, and third laminated layers, and wherein 10 atomic well and barrier layers are alternately laminated in said first layer, 6 atomic well and barrier layers are alternately laminated in said second layer, and 4 atomic well and barrier layers are alternately laminated in said third layer.
Claim 33
Dependent Claim 89 words
The semiconductor laser unit according to claim 25, wherein one said multiquantum barrier layer is composed of first, second, and third laminated layers, and wherein well and barrier layers, the thickness of which is respectively 25 to 35 Å, are alternately laminated in said first layer, well and barrier layers, the thickness of which is respectively 15 to 25 Å, are alternately laminated in said second layer, and well and barrier layers, the thickness of which is respectively 10 to 15 Å, are alternately laminated in said third layer.

References Cited (Backward Citations)

JPS6346788A Cited
JPH04114486A Cited
US5319660A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-06-12 1998-12-12 1999-06-13 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-06-12 2002-12-12 2003-06-13 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-06-12 2006-12-12 2007-06-13 $7700.00 Window Closed / Lapsed

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