Light-emitting device having a gain region and a reflector

• US 8,629,460 B2
• Filed: 12/28/2012
• Issued: 01/14/2014
• 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:
  US13/729,306
• Publication Number:
  US 20130134389A1
• Time in Patent Office: 382 Days
• Field of Search: 257 75- 81
• 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

A light-emitting device has a first cladding layer, an active layer formed above the first cladding layer, a second cladding layer formed above the active layer, a gain region, and a reflecting part. The active layer has first and second side surfaces parallel to each other. The gain region has a first end surface disposed on the first side surface. The gain region also has a second end surface disposed inside from the second side surface and angled relative to the second side surface. The second end surface, the gain region and the first end surface are provided in a first normal direction relative to the second end surface. The reflecting part is disposed next to the second end surface.

Claims

1. A light-emitting device comprising:

a first cladding layer;

an active layer formed above the first cladding layer;

a second cladding layer formed above the active layer;

a first electrode electrically connected to the first cladding layer;

a second electrode electrically connected to the second cladding layer;

a gain region, which generates light by applying a voltage, provided at a portion of the active layer, and

a reflecting part reflecting the light generated in the gain region, wherein

the active layer has a first side surface, and a second side surface that are parallel to each other,

the gain region has a first end surface disposed on the first side surface, and the gain region has a second end surface disposed inside from the second side surface side and angled relative to the first side surface,

the second end surface, the gain region and the first end surface are provided in a first normal direction relative to the second end surface,

the reflecting part is disposed next to the second end face, and

the second electrode is formed in a region excluding a region of the reflecting part in a plan view.

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 1, wherein the reflecting part includes a plurality of grooves disposed at predetermined intervals.

4. The light-emitting device according to claim 3, wherein the plurality of grooves are rectangular, and a pair of sides facing the plurality of grooves is parallel to the second end surface.

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

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

7. The light-emitting device according to claim 1, wherein the reflecting part 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 first normal direction.

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

9. The light-emitting device according to claim 1, further comprising a low-reflectivity film disposed on the first end surface.

10. The light-emitting device according to claim 9, wherein the low-reflectivity film is an antireflection film.

11. The light-emitting device according to claim 1, wherein the first end surface and the second end surface is not overlapped each other in a second normal direction relative to the first side surface.

12. The light-emitting device according to claim 1, wherein the gain region is in a stripe shape.

13. The light-emitting device according to claim 1, wherein a plurality of gain regions are provided.