SURFACE-EMITTING LASER DEVICE AND SURFACE-EMITTING LASER ARRAY INCLUDING SAME

• US 20100150195A1
• Filed: 02/25/2010
• Published: 06/17/2010
• Est. Priority Date: 02/03/2006
• Status: Active Grant

• Current Assignee: Shunichi Sato
• Original Assignee: Shunichi Sato
• Inventors: SATO, Shunichi
• Granted Patent: US 8,325,777 B2
• Time in Patent Office: Days
• US Class Current: 372/45.10
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01S 5/02461 Structure or details of the laser chip to manipulate the heat flow, e.g. passive layers in the chip with a low heat conductivity
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18358 containing spacer layers to adjust the phase of the light wave in the cavity
• CPC Class Codes: H01S 5/3403 having a strained layer structure in which the strain performs a special function, e.g. general strain effects, strain versus polarisation
• CPC Class Codes: H01S 5/3434 with a well layer comprising at least both As and P as V-compounds
• CPC Class Codes: H01S 5/3436 based on InGa(Al)P

Abstract

A surface-emitting laser device is disclosed that includes a substrate connected to a heat sink; a first reflective layer formed of a semiconductor distributed Bragg reflector on the substrate; a first cavity spacer layer formed in contact with the first reflective layer; an active layer formed in contact with the first cavity spacer layer; a second cavity spacer layer formed in contact with the active layer; and a second reflective layer formed of a semiconductor distributed Bragg reflector in contact with the second cavity spacer layer. The first cavity spacer layer includes a semiconductor material having a thermal conductivity greater than the thermal conductivity of a semiconductor material forming the second cavity spacer layer.

Claims

1. A surface-emitting laser device, comprising:

a first reflective layer formed of a semiconductor distributed Bragg reflector on a substrate;

a first cavity spacer layer formed in contact with the first reflective layer;

an active layer formed in contact with the first cavity spacer layer;

a second cavity spacer layer formed in contact with the active layer; and

a second reflective layer formed of a semiconductor distributed Bragg reflector in contact with the second cavity spacer layer,

wherein the first reflective layer includes a plurality of low refractive index layers and the second reflective layer includes a plurality of low refractive index layers; and

a thermal conductivity of a semiconductor material of one of the low refractive index layers of the first reflective layer which one is disposed closest to the active layer is greater than a thermal conductivity of a semiconductor material of one of the low refractive index layers of the second reflective layer which one is disposed closest to the active layer;

wherein;

the one of the low refractive index layers of the second reflective layer which one is disposed closest to the active layer includes (Al_eGa_1-e)_fIn_1-fP (0<

e≦

1, 0≦

f≦

1);

the one of the low refractive index layers of the first reflective layer which one is disposed closest to the active layer includes Al_xGa_1-xAs (0<

x≦

1) having the thermal conductivity greater than the thermal conductivity of said (Al_eGa_1-e)_fIn_1-fP; and

the substrate is connected to a heat sink.

2. The surface-emitting laser device as claimed in claim 1, wherein said Al_xGa_1-xAs is AlAs.

3. The surface-emitting laser device as claimed in claim 1, wherein a part of at least one of the first and second cavity spacer layers is formed of AlGaInP.

4. The surface-emitting laser device as claimed in claim 1, wherein:

the active layer includes

a well layer formed of Ga_aIn_1-aP_bAs_1-b, (0≦

a≦

1, 0≦

b≦

1); and

a barrier layer formed of (Ga_cIn_1-c)_dP_1-dAs (0≦

c≦

1, 0≦

d≦

1) having a band gap greater than a band gap of the well layer;

the plurality of low refractive index layers of the first reflective layer are formed of Al_xGa_1-xAs (0<

x≦

1);

the first reflective layer further includes a plurality of high refractive index layers formed of Al_yGa_1-yAs (0<

y<

x≦

1); and

a part of at least one of the first and second cavity spacer layers is formed of AlGaInP.

5. The surface-emitting laser device as claimed in claim 4, wherein each of the low refractive index layers included in the first reflective layer includes AlAs.

6. A surface-emitting laser device as claimed in claim 1,

wherein the first cavity spacer layer includes a semiconductor material having a thermal conductivity greater than a thermal conductivity of a semiconductor material forming the second cavity spacer layer.

7. The surface-emitting laser device as claimed in claim 6, wherein the semiconductor material forming the second cavity spacer layer includes (Al_dGa_1-d)_kIn_1-kP (0<

d≦

1, 0≦

k≦

1).

8. The surface-emitting laser device as claimed in claim 7, wherein the semiconductor material forming the first cavity spacer layer has the thermal conductivity greater than the thermal conductivity of said (Al_dGa_1-d)_kIn_1-kP.

9. The surface-emitting laser device as claimed in claim 8, wherein the first cavity spacer layer includes (Al_gGa_1-g)_hIn_1-hP (0≦

g≦

1, 0≦

h≦

1) having a band gap smaller than a band gap of said (Al_dGa_1-d)_kIn_1-kP.

10. The surface-emitting laser device as claimed in claim 1, further comprising:

a third reflective layer formed of a semiconductor distributed Bragg reflector in contact with the second reflective layer;

wherein;

the third reflective layer is formed by an AlGaAs-system material, and

the second reflective layer includes a layered body of m low reflective index layers formed of (Al_xGa_1-x)_0.5In_0.5P (0≦

x≦

1) and m high refractive index layers formed of (Al_yGa_1-y)_0.5In_0.5P (0≦

y<

x≦

1).

11. A surface-emitting laser array, comprising:

a plurality of surface-emitting laser devices,

wherein each of the surface-emitting laser devices is formed of the surface-emitting laser device as set forth in claim 1.

12. An image forming apparatus, comprising:

a surface-emitting laser array as a light source for writing, the surface-emitting laser array including a plurality of surface-emitting laser devices,

wherein each of the surface-emitting laser devices, is formed of the surface-emitting laser device as set forth in claim 1.

13. An optical pickup unit, comprising:

the surface-emitting laser device as set forth in claim 1 as a light source.

14. An optical pickup unit, comprising:

a surface-emitting laser array as a light source, the surface-emitting laser array including a plurality of surface-emitting laser devices,

wherein each of the surface-emitting laser devices is formed of the surface-emitting laser device as set forth in claim 1.

15. An optical transmitter module, comprising;

the surface-emitting laser device as set forth in claim 1 as a light source.

16. An optical transmitter module, comprising;

a surface-emitting laser array as a light source, the surface-emitting laser array including a plurality of surface-emitting laser devices,

wherein each of the surface-emitting laser devices is formed of the surface-emitting laser device as set forth in claim 1.

17. An optical transmitter receiver module, comprising:

the surface-emitting laser device as set forth in claim 1 as a light source.

18. An optical transmitter receiver module, comprising:

a surface-emitting laser array as a light source, the surface-emitting laser array including a plurality of surface-emitting laser devices,

wherein each of the surface-emitting laser devices is formed of the surface-emitting laser device as set forth in claim 1.

19. An optical communication system, comprising:

the surface-emitting laser device as set forth in claim 1 as a light source.

20. An optical communication system, comprising:

a surface-emitting laser array as a light source, the surface-emitting laser array including a plurality of surface-emitting laser devices,

wherein each of the surface-emitting laser devices is formed of the surface-emitting laser device as set forth in claim 1.