# US 7,609,739 B2 · Semiconductor laser device

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- Number: US 7,609,739 B2
- Document ID: US7609739B2
- Status: Granted
- Kind: B2
- Application number: 11/850,939
- Filed: 2007-09-06
- Published: 2008-03-13
- Granted: 2009-10-27
- Earliest claimed: 2006-09-06
- Assignees: Kabushiki Kaisha Toshiba
- Inventors: Akira Tanaka
- Web page: https://patentgrep.com/patent/US7609739B2

## CPC

- H01S 5/34333: {with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser}
- B82Y 20/00: Nanooptics, e.g. quantum optics or photonic crystals
- H01S 5/1039: {Details on the cavity length}
- H01S 5/2004: {Confining in the direction perpendicular to the layer structure}
- H01S 5/22: having a ridge or stripe structure
- H01S 5/2222: {having special electric properties}
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

A semiconductor laser device includes: an active layer having a single or multiple quantum well structure including a well layer of InwGa1-wN (0.08≦w≦0.2) and a barrier layer of InbGa1-bN (0.01≦b≦0.05); a cladding layer of AlyGa1-yN (0≦y≦0.1) provided on the active layer, the cladding layer including a ridge portion extending like a stripe in axial direction of an optical cavity and a non-ridge portion located on both sides of the ridge portion; and an overflow blocking layer of AlzGa1-zN (y<z) provided between the active layer and the cladding layer. A thickness of D (μm) of the non-ridge portion and an axial length of L (μm) of the optical cavity satisfies formulas L≧750−400×(D/0.01) and 0<D≦0.01.

## Claims

### Claim 1

A semiconductor laser device, comprising:
an active layer having a single or multiple quantum well structure including a well layer of InwGa1-wN (0.08≦w≦0.2) and a barrier layer of InbGa1-bN (0.01≦b≦0.05);
a cladding layer of AlyGa1-yN (0≦y≦0.1) provided on the active layer, the cladding layer including a ridge portion extending like a stripe in axial direction of an optical cavity and a non-ridge portion located on both sides of the ridge portion; and
an overflow blocking layer of AlzGa1-zN (y<z) provided between the active layer and the cladding layer,
a thickness of D (μm) of the non-ridge portion and an axial length of L (μm) of the optical cavity satisfying formulas
L≧750−400×(D/0.01)
and
0<D≦0.01,
wherein a full width at half maximum of a horizontal far field pattern of a beam emitted from the active layer has a width of not less than 9.2 degrees.

### Claim 2 (depends on 1)

The semiconductor laser device according to claim 1, wherein the overflow blocking layer has an acceptor concentration of 1×1020 cm−3 or more.

### Claim 3 (depends on 1)

The semiconductor laser device according to claim 1, wherein the ridge portion has a width of not less than 1.5 μm and not more than 2.5 μm.

### Claim 4 (depends on 1)

The semiconductor laser device according to claim 1, wherein the ridge portion has a width of not more than 2.0 μm, and a formula
L≦1200−400×(D/0.01)
is satisfied.

### Claim 5 (depends on 1)

The semiconductor laser device according to claim 1, wherein the ridge portion has a width of not more than 1.8 μm, and a formula
L≧1000−400×(D/0.01)
is satisfied.

### Claim 6 (depends on 1)

The semiconductor laser device according to claim 1, wherein a full width at half maximum of the horizontal far field pattern of a beam emitted from the active layer has a width of not more than 11 degrees.

### Claim 7 (depends on 1)

The semiconductor laser device according to claim 1, wherein a full width at half maximum of a vertical far field pattern of a beam emitted from the active layer has a width of not less than 17 degrees and not more than 23 degrees.

### Claim 8 (depends on 1)

The semiconductor laser device according to claim 1, wherein a ratio of a full width at half maximum of the vertical far field pattern to a full width at half maximum of the horizontal far field pattern of a beam emitted from the active layer has a width of not less than 1.54 and not more than 2.5.

### Claim 9

A semiconductor laser device, comprising:
a first cladding layer including n-type AlGaN;
a first light guide layer including GaN and provided on the first cladding layer;
an active layer provided on the first light guide layer;
an overflow blocking layer provided on the active layer;
a second light guide layer including GaN and provided on the overflow blocking layer;
a second cladding layer provided on the second light guide layer including a ridge portion extending like a stripe in axial direction of an optical cavity and a non-ridge portion located on both sides of the ridge portion;
a contact layer including p+-type GaN and provided on the ridge portion; and
an insulator layer provided on the both side faces of the ridge portion and the contact layer, and a upper face of the non-ridge portion,
the active layer having a single or multiple quantum well structure including a well layer of InwGa1-wN (0.08≦w≦0.2) and a barrier layer of InbGa1-bN (0.01≦b≦0.05),
the second cladding layer including AlyGa1-yN (0≦y≦0.1),
the overflow blocking layer including AlzGa1-zN (y<z), and
a thickness of D (μm) of the non-ridge portion and an axial length of L (μm) of the optical cavity satisfying formulas
L≧750−400×(D/0.01)
and
0<D≦0.01,
wherein a full width at half maximum of a horizontal far field pattern of a beam emitted from the active layer has a width of not less than 9.2 degrees.

### Claim 10 (depends on 9)

The semiconductor laser device according to claim 9, wherein the overflow blocking layer has an acceptor concentration of 1×1020 cm−3 or more.

### Claim 11 (depends on 9)

The semiconductor laser device according to claim 9, wherein the ridge portion has a width of not less than 1.5 μm and not more than 2.5 μm.

### Claim 12 (depends on 9)

The semiconductor laser device according to claim 9, wherein the ridge portion has a width of not more than 2.0 μm, and a formula
L≧1200−400×(D/0.01)
is satisfied.

### Claim 13 (depends on 9)

The semiconductor laser device according to claim 9, wherein the ridge portion has a width of not more than 1.8 μm, and a formula
L≧1000−400×(D/0.01)
is satisfied.

### Claim 14 (depends on 9)

The semiconductor laser device according to claim 9, wherein a full width at half maximum of the horizontal far field pattern of a beam emitted from the active layer has a width of not more than 11 degrees.

### Claim 15 (depends on 9)

The semiconductor laser device according to claim 9, wherein a full width at half maximum of a vertical far field pattern of a beam emitted from the active layer has a width of not less than 17 degrees and not more than 23 degrees.

### Claim 16

A semiconductor laser devices comprising:
a substrate having a first electrode on a first surface of the substrate;
a first cladding layer including n-type AlGaN and provided on a second surface of the substrate;
a first light guide layer including GaN and provided on the first cladding layer;
an active layer provided on the first light guide layer;
an overflow blocking layer provided on the active layer;
a second light guide layer including GaN and provided on the overflow blocking layer;
a second cladding layer provided on the second light guide layer including a ridge portion extending like a stripe in axial direction of an optical cavity and a non-ridge portion located on both sides of the ridge portion;
a contact layer including p+-type GaN provided on the ridge portion;
an insulator layer provided on the both side faces of the ridge portion and the contact layer, and a upper face of the non-ridge portion; and
a second electrode provided on the contact layer and the insulator,
the active layer having a single or multiple quantum well structure including a well layer of InwGa1-wN (0.08≦w≦0.2) and a barrier layer of InbGa1-bN (0.01≦b≦0.05),
the cladding layer including AlyGa1-yN (0≦y≦0.1),
the overflow blocking layer including AlzGa1-zN (y<z), and
a thickness of D (μm) of the non-ridge portion and an axial length of L (μm) of the optical cavity satisfying formulas
L≧750−400×(D/0.01)
and
0<D≦0.01,
wherein a full width at half maximum of a horizontal far field pattern of a beam emitted from the active layer has a width of not less than 9.2 degrees.

### Claim 17 (depends on 16)

The semiconductor laser device according to claim 16, wherein the overflow blocking layer has an acceptor concentration of 1×1020 cm−3 or more.

### Claim 18 (depends on 16)

The semiconductor laser device according to claim 16, wherein the ridge portion has a width of not less than b 1.5 μm and not more than 2.5 μm.

### Claim 19 (depends on 16)

The semiconductor laser device according to claim 16, wherein the ridge portion has a width of not more than 2.0 μm, and a formula
L≧1200−400×(D/0.01)
is satisfied.

### Claim 20 (depends on 16)

The semiconductor laser device according to claim 16, wherein the ridge portion has a width of not more than 1.8 μm, and a formula
L≧1000−400×(D/0.01)
is satisfied.