Optical semiconductor device

Patent metadata

Field	Value
Publication number	US-10784649-B2
Application number	US-201716474344-A
Country	US
Kind code	B2
Filing date	Mar 23, 2017
Priority date	Mar 23, 2017
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

Abstract

A semiconductor laser (2) includes an n-type semiconductor substrate (1), a stack of an n-type cladding layer (4), an active layer (5), and a p-type cladding layer (6) successively stacked on the n-type semiconductor substrate (1). An optical waveguide (3) includes a non-impurity-doped core layer (9) provided on a light output side of the semiconductor laser (2) on the n-type semiconductor substrate (1) and having a larger forbidden band width than the active layer (5), and a cladding layer (10) provided on the core layer (9) and having a lower carrier concentration than the p-type cladding layer (6). The semiconductor laser (2) includes a carrier injection region (X1), and a non-carrier-injection region (X2) provided between the carrier injection region (X1) and the optical waveguide (3).

First claim

The invention claimed is:

1. An optical semiconductor device comprising:
a semiconductor laser including an n-type semiconductor substrate, a stack of an n-type cladding layer, an active layer, and a p-type cladding layer successively stacked on the n-type semiconductor substrate; and
an optical waveguide including a non-impurity-doped core layer provided on a light output side of the semiconductor laser on the n-type semiconductor substrate and having a larger forbidden band width than the active layer, and a cladding layer provided on the core layer and having a lower carrier concentration than the p-type cladding layer,
wherein the semiconductor laser includes a carrier injection region, and a non-carrier-injection region provided between the carrier injection region and the optical waveguide.

2. The optical semiconductor device according to claim 1 , further comprising an electrode provided in the carrier injection region on a lower surface of the n-type semiconductor substrate and not provided in the non-carrier-injection region and the optical waveguide.

3. The optical semiconductor device according to claim 1 , further comprising an insulator provided on a lower surface of the n-type semiconductor substrate in the non-carrier-injection region and the optical waveguide.

4. The optical semiconductor device according to claim 1 , further comprising a metal oxide film provided on a lower surface of the n-type semiconductor substrate in the non-carrier-injection region and the optical waveguide.

5. The optical semiconductor device according to claim 1 , further comprising a metal layer Schottky-bonded to a lower surface of the n-type semiconductor substrate in the non-carrier-injection region and the optical waveguide.

6. The optical semiconductor device according to claim 1 , further comprising a p-type semiconductor layer provided on a lower surface of the n-type semiconductor substrate in the non-carrier-injection region and the optical waveguide.

7. The optical semiconductor device according to claim 1 , wherein a lower surface of the n-type semiconductor substrate is flat in the semiconductor laser and the optical waveguide.

8. The optical semiconductor device according to claim 1 , wherein a recess is formed in the lower surface of the n-type semiconductor substrate in the non-carrier-injection region and the optical waveguide.

9. An optical semiconductor device comprising:
a semiconductor laser including an n-type semiconductor substrate, a stack of an n-type cladding layer, an active layer, and a p-type cladding layer successively stacked on the n-type semiconductor substrate; and
an optical waveguide including a non-impurity-doped core layer provided on a light output side of the semiconductor laser on the n-type semiconductor substrate and having a larger forbidden band width than the active layer, a cladding layer provided on the core layer and having a lower carrier concentration than the p-type cladding layer, and a p-type semiconductor layer provided below the core layer and not in contact with a lower surface of the n-type semiconductor substrate.

Assignees

• Mitsubishi Electric Corp

Inventors

• Sakaino Go
• Nakamura Naoki
• Okunuki Yuichiro

Classifications

• H01S5/12

  the resonator having a periodic structure, e.g. in distributed feedback [DFB] lasers (comprising a photonic bandgap structure H01S5/11; surface-emitting lasers H01S5/18) · CPC title

• H01S5/2222

  having special electric properties · CPC title

• H01S5/32333

  based on InGaAsP · CPC title

• H01S5/04256 Primary

  characterised by the configuration · CPC title

• H01S5/2018

  Optical confinement, e.g. absorbing-, reflecting- or waveguide-layers · CPC title