High thermal conductivity vertical cavity surface emitting laser (VCSEL)

• US 20050271113A1
• Filed: 06/07/2004
• Published: 12/08/2005
• Est. Priority Date: 06/07/2004
• Status: Active Grant

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Avago Technologies Fiber IP Singapore PTE Limited (Broadcom, Inc.)
• Inventors: Tan, Michael R. T., Leary, Michael H., Song, Yoon K.
• Granted Patent: US 7,372,886 B2
• Time in Patent Office: Days
• US Class Current: 372/98
• 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 5/0421 characterised by the semiconducting contacting layers electrodes H01S5/0425
• CPC Class Codes: H01S 5/18308 having a special structure for lateral current or light confinement
• CPC Class Codes: H01S 5/18327 Structure being part of a DBR H01S5/18391 takes precedence

Abstract

A light generating device such as a VCSEL includes a light generation layer, a top reflector, a bottom reflector, and a high thermal conductivity (HTC) layer between the light generation layer and the bottom reflector. The light generation layer is adapted to generate light having a first wavelength. Heat produced at the light generation layer is more efficiently dissipated due to the presence of the HTC layer. Alternatively, a light generating device such as a VCSEL includes a light generation layer, a top reflector, and a high thermal conductivity (HTC) bottom reflector. Heat produced at the light generation layer is more efficiently dissipated due to the fact that the bottom reflector is a HTC DBR reflector having lower thermal resistivity than a conventional DBR reflector.

Claims

1. A light generating device comprising:

a light generation layer adapted to generate light having a known wavelength;

a top reflector above said light generation layer;

a bottom reflector below said light generation layer; and

at least one of a high thermal conductivity (HTC) layer between said light generation layer and said bottom reflector and a high thermal conductivity (HTC) layer between said light generation layer and said top reflector.

2. The light generating device recited in claim 1 wherein said top reflector is a distributed Bragg reflector (DBR).

3. The light generating device recited in claim 1 wherein said HTC layer is an integer multiple of one-half wavelength thick.

4. The light generating device recited in claim 1 wherein said HTC layer comprises an element selected from a group consisting of Aluminum Arsenide, Gallium Arsenide, and Indium phosphide.

5. The light generating device recited in claim 1 further comprising a first electrode connected to said top reflector and a second electrode connected to said bottom reflector.

6. The light generating device recited in claim 1 further comprising a contact layer adapted to provide electronic contact between an electrode and said light generation layer.

7. The light generating device recited in claim 6 further comprising an etch stop layer in connection with said contact layer.

8. A light generating device comprising:

a light generation layer adapted to generate light having a known wavelength;

a top reflector above said light generation layer; and

a high thermal conductivity (HTC) bottom reflector below said light generation layer.

9. The light generating device recited in claim 8 wherein said HTC bottom reflector comprises at least one distributed Bragg reflector (DBR) layer pair.

10. The light generating device recited in claim 9 wherein the distributed Bragg reflector (DBR) pairs comprise high thermal conductivity material.

11. The light generating device recited in claim 9 wherein each of the HTC DBR layer pair comprises a first layer having a first thermal conductivity and having a first thickness that is a quarter of the known wavelength, and a second layer having a second thermal conductivity and having a second thickness that is an odd multiple of quarter of the known wavelength.

12. The light generating device recited in claim 11 wherein the second thermal conductivity is higher than the first thermal conductivity.

13. The light generating device recited in claim 11 wherein the second layer comprises Aluminum Arsenide.

14. The light generating device recited in claim 9 wherein each of the HTC layer pair comprises a first layer having a first thermal conductivity and having a first thickness that is a quarter of the known wavelength, and a second layer having a second thermal conductivity and having a second thickness that is an odd multiple of quarter of the known wavelength.

15. The light generating device recited in claim 14 wherein the second thermal conductivity is higher than the first thermal conductivity.

16. The light generating device recited in claim 14 wherein the second layer comprises Aluminum Arsenide.

17. The light generating device recited in claim 9 wherein said HTC bottom reflector comprises non-uniform HTC layer pairs.

18. The light generating device recited in claim 17 wherein said HTC bottom reflector comprises a first HTC layer pair, the first HTC layer pair including a first layer having a first thermal conductivity and having a first thickness that is a quarter of the known wavelength, and a second layer having a second thermal conductivity and having a second thickness that is an odd multiple of quarter of the known wavelength.

19. The light generating device recited in claim 18 wherein said HTC bottom reflector comprises a second HTC layer pair, the second HTC layer pair including a third layer having the first thermal conductivity and having the first thickness, and a fourth layer having the second thermal conductivity and having a third thickness that is an odd multiple of quarter of the known wavelength, the third thickness different than the second thickness.

20. The light generating device recited in claim 19 wherein said HTC bottom reflector comprises a third HTC layer pair, the third HTC layer pair including a fifth layer having the first thermal conductivity and having the first thickness, and a sixth layer having the second thermal conductivity and having a fourth thickness that is an odd multiple of quarter of the known wavelength, the fourth thickness different from the third or the second thicknesses.