Light-emitting device having a gain region and a reflector

• US 8,106,405 B2
• Filed: 12/15/2009
• Issued: 01/31/2012
• Est. Priority Date: 12/19/2008
• Status: Active Grant

• Current Assignee: Seiko Epson Corporation (Seiko Group)
• Original Assignee: Seiko Epson Corporation (Seiko Group)
• Inventors: Nagawa, Michifumi
• Primary Examiner(s): HA, NATHAN W
• Application Number:
  US12/638,106
• Publication Number:
  US 20100155759A1
• Time in Patent Office: 777 Days
• Field of Search: 257 75-101, 257/E33.055
• US Class Current: 257/79
• CPC Class Codes: H01L 33/0045 the devices being superluminescent diodes
• CPC Class Codes: H01L 33/10 with a light reflecting structure, e.g. semiconductor Bragg reflector
• CPC Class Codes: H01L 33/14 with a carrier transport control structure, e.g. highly-doped semiconductor layer or current-blocking structure
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

The light-emitting device of the present invention has a first cladding layer; an active layer formed above the first cladding layer; and a second cladding layer formed above the active layer, wherein the active layer has a first side surface, and a second side surface parallel to the first side surface; at least a portion of the active layer constitutes a gain region; the gain region has a first end surface disposed on the first side surface side and a second end surface disposed on the second side surface side, and extends from the first end surface to the second end surface in the direction inclined to the normal to the first side surface as viewed from above; the second end face is orthogonal to the direction in which the gain region extends as viewed from above; a reflecting part is disposed on the second end face; and a part of the light generated in the gain region is reflected in the reflecting part disposed on the second end face and is emitted from the first end surface.

Claims

1. A light-emitting device comprising:

a first cladding layer;

an active layer formed above the first cladding layer; and

a second cladding layer formed above the active layer, wherein

the active layer has a first side surface, and a second side surface parallel to the first side surface;

at least a portion of the active layer constitutes a gain region;

the gain region has a first end surface disposed on the first side surface side and a second end surface disposed on the second side surface side, and extends from the first end surface to the second end surface in the direction inclined to the normal to the first side surface as viewed from above;

the second end face is orthogonal to the direction in which the gain region extends as viewed from above;

a reflecting part is disposed on the second end face; and

a part of the light generated in the gain region is reflected in the reflecting part disposed on the second end face and is emitted from the first end surface.

2. The light-emitting device according to claim 1, wherein the reflecting part is a distributed Bragg reflecting mirror.

3. The light-emitting device according to claim 2, wherein the distributed Bragg reflecting mirror includes a plurality of grooves disposed at predetermined intervals.

4. The light-emitting device according to claim 3, wherein the grooves are rectangular as viewed from above, and a pair of sides facing the grooves is parallel to the second end face.

5. The light-emitting device according to claim 3, wherein the position of the bottom surface of the grooves is disposed below the position of the lower surface of the active layer.

6. The light-emitting device according to claim 3, wherein the position of the bottom surface of the grooves is disposed above the position of the upper surface of the active layer.

7. The light-emitting device according to claim 2, wherein the distributed Bragg reflecting mirror includes a dielectric multilayer film in which a high-refractive index layer and a low-refractive index layer are layered in alternating fashion in the direction in which the gain region extends.

8. The light-emitting device according to claim 1, wherein the reflecting part is a metal mirror.

9. The light-emitting device of claim 1, wherein an antireflection film is disposed on the first end surface.

10. The light-emitting device of claim 1, wherein the gain region does not overlap the first end surface and the second end surface as viewed from above from the first side surface side.

11. The light-emitting device of claim 1, wherein a plurality of gain regions is provided.

12. The light-emitting device of claim 1, comprising:

a first electrode electrically connected to the first cladding layer; and

a second electrode electrically connected to the second cladding layer.