Single mode VCSEL

• US 20040042518A1
• Filed: 09/03/2002
• Published: 03/04/2004
• Est. Priority Date: 09/03/2002
• Status: Active Grant

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Finisar Corporation (II-VI Incorporated)
• Inventors: Johnson, Ralph H., Guenter, James K., Tatum, James A.
• Granted Patent: US 6,965,626 B2
• Time in Patent Office: Days
• US Class Current: 372/46
• CPC Class Codes: H01S 2301/166 Single transverse or lateral mode
• CPC Class Codes: H01S 5/005 Optical components external to the laser cavity, specially adapted therefor, e.g. for homogenisation or merging of the beams or for manipulating laser pulses, e.g. pulse shaping H01S5/026, H01S5/18388 take precedence
• CPC Class Codes: H01S 5/0207 Substrates having a special shape
• CPC Class Codes: H01S 5/18305 with emission through the substrate, i.e. bottom emission
• CPC Class Codes: H01S 5/1833 with more than one structure
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/18369 based on dielectric materials

Abstract

A VCSEL having a metallic heat spreading layer adjacent a semiconductor buffer layer containing an insulating structure. The heat spreading layer includes an opening that enables light emitted by an active region to reflect from a distributed Bragg reflector (DBR) top mirror located above the heat spreading layer. A substrate is below the active region. A lower contact provides electrical current to that substrate. The lower contact includes an opening that enables light emitted from the active region to reflect from a distributed Bragg reflector (DBR) lower mirror. Beneficially, the substrate includes a slot that enables light to pass through an opening in the lower contact. That slot acts as an alignment structure that enables optical alignment of an external feature to the VCSEL.

Claims

1. A vertical cavity surface emitting laser, comprising:

an active region;

a doped semiconductive top buffer layer adjacent said active region, said top buffer having an insulating structure;

a top metallic contact over part of said top buffer layer; and

a top distributed Bragg reflector over said top buffer layer;

wherein said insulating structure is for guiding current applied to said top metallic contact into said active region;

wherein said active region is for emitting light in response to applied current;

wherein said top distributed Bragg reflector is for reflecting light from said active region back into said active region; and

wherein said top metallic contact is for spreading heat produced in said active region.

2. A vertical cavity surface emitting laser according to claim 1, further including a tunnel junction disposed between said active region and said top buffer layer.

3. A vertical cavity surface emitting laser according to claim 1, wherein said active region has at least one quantum well.

4. A vertical cavity surface emitting laser according to claim 1, further including a substrate adjacent said active layer.

5. A vertical cavity surface emitting laser according to claim 4, further including a bottom metallic contact over part of said substrate;

and

a bottom distributed Bragg reflector in optical contact with said substrate.

6. A vertical cavity surface emitting laser according to claim 5, wherein said bottom metallic contact is ring-shaped.

7. A vertical cavity surface emitting laser according to claim 5, wherein said bottom distributed Bragg reflector extends over said bottom metallic contact.

8. A vertical cavity surface emitting laser according to claim 5, wherein said substrate includes a cavity, and wherein said bottom distributed Bragg reflector has a surface within said cavity.

9. A vertical cavity surface emitting laser according to claim 8, wherein said bottom metallic contact surrounds said cavity.

10. A vertical cavity surface emitting laser according to claim 1, further including a lower buffer layer in contact with said active region.

11. A vertical cavity surface emitting laser according to claim 10, further including a substrate in contact with said lower buffer layer.

12. A vertical cavity surface emitting laser according to claim 11, further including:

a bottom metallic contact over part of said substrate; and

a bottom distributed Bragg reflector in optical contact with said substrate.

13. A vertical cavity surface emitting laser according to claim 12, wherein said bottom metallic contact is ring-shaped.

14. A vertical cavity surface emitting laser according to claim 12, wherein said substrate includes a cavity, and wherein said bottom distributed Bragg reflector has a surface within said cavity.

15. A vertical cavity surface emitting laser according to claim 14, wherein said opaque bottom metallic contact surrounds said cavity.

16. A vertical cavity surface emitting laser according to claim 14, wherein said cavity is defined by inwardly sloping walls.

17. A vertical cavity surface emitting laser according to claim 14, wherein said cavity is aligned with emitted light.

18. A vertical cavity surface emitting laser according to claim 17, further including an external structure that extends into said cavity.

19. A vertical cavity surface emitting laser according to claim 1, wherein said insulating structure includes an oxide region.

20. A vertical cavity surface emitting laser according to claim 1, wherein said insulating structure is an ion implanted region.