Surface-emitting semiconductor laser, surface-emitting semiconductor laser device, optical transmission device, and information processing device

Patent metadata

Field	Value
Publication number	US-9502863-B2
Application number	US-201514795987-A
Country	US
Kind code	B2
Filing date	Jul 10, 2015
Priority date	Aug 26, 2014
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

Provided is a surface-emitting semiconductor laser including a substrate; a first semiconductor multilayer reflector of a first conductivity type formed on the substrate, the first semiconductor multilayer reflector including plural pairs of a low-refractive-index layer and a high-refractive-index layer; a cavity region formed on the first semiconductor multilayer reflector; a second semiconductor multilayer reflector of a second conductivity type formed on the cavity region, the second semiconductor multilayer reflector including plural pairs of a low-refractive-index layer and a high-refractive-index layer; a columnar structure extending from the second semiconductor multilayer reflector to the cavity region; and a current confinement layer formed inside the columnar structure by selective oxidation of a semiconductor layer containing Al. The cavity region includes an active region; and a cavity extension region interposed between the active region and the first semiconductor multilayer reflector.

First claim

What is claimed is:

1. A surface-emitting semiconductor laser comprising:
a substrate;
a first semiconductor multilayer reflector of a first conductivity type formed on the substrate, the first semiconductor multilayer reflector including a plurality of pairs of a low-refractive-index layer and a high-refractive-index layer;
a cavity region formed on the first semiconductor multilayer reflector;
a second semiconductor multilayer reflector of a second conductivity type formed on the cavity region, the second semiconductor multilayer reflector including a plurality of pairs of a low-refractive-index layer and a high-refractive-index layer;
a columnar structure extending from the second semiconductor multilayer reflector to the cavity region; and
a current confinement layer formed inside the columnar structure by selective oxidation of a semiconductor layer containing Al,
wherein the cavity region includes
an active region; and
a cavity extension region interposed between the active region and the first semiconductor multilayer reflector,

wherein the bottom of the columnar structure is positioned within the cavity extension region in the film-thickness direction,
wherein the cavity extension region is composed of Al x Ga 1-x As, where x represents an Al content, the Al content being set such that the cavity extension region is not substantially subject to oxidation or the degree of oxidation of the cavity extension region is negligible, and
wherein the low-refractive-index layer constituting the first semiconductor multilayer reflector has an Al content equal to or higher than an Al content in the current confinement layer.

2. The surface-emitting semiconductor laser according to claim 1 ,
wherein a concentration of an impurity of the first conductivity type in the cavity extension region is lower than an impurity concentration in the first semiconductor multilayer reflector.

3. The surface-emitting semiconductor laser according to claim 1 ,
wherein the cavity extension region further includes a carrier block layer adjacent to the active region, the carrier block layer having a higher Al content than the active region.

4. The surface-emitting semiconductor laser according to claim 1 ,
wherein the cavity extension region is composed of Al x Ga 1-x As, where x≦0.95.

5. The surface-emitting semiconductor laser according to claim 3 ,
wherein the carrier block layer is composed of Al y Ga 1-y As, where 0.8<y≦0.95.

6. The surface-emitting semiconductor laser according to claim 3 ,
wherein the carrier block layer has a higher impurity concentration than any other region constituting the cavity extension region.

7. The surface-emitting semiconductor laser according to claim 3 ,
wherein the carrier block layer has a lower Al content than any other region constituting the cavity extension region.

8. The surface-emitting semiconductor laser according to claim 3 ,
wherein the carrier block layer has a higher Al content than any other region constituting the cavity extension region.

9. The surface-emitting semiconductor laser according to claim 3 ,
wherein a concentration of an impurity of the first conductivity type in the carrier block layer is lower than an impurity concentration in the first semiconductor multilayer reflector.

10. The surface-emitting semiconductor laser according to claim 1 ,
wherein the cavity extension region has a thickness larger than a range of production fluctuations resulting from etching of the columnar structure.

11. The surface-emitting semiconductor laser according to claim 1 ,
wherein the cavity extension region has an optical thickness equal to an integral multiple of λ/4, where λ represents oscillation wavelength.

12. The surface-emitting semiconductor laser according to claim 1 ,
wherein the cavity extension region has an optical thickness equal to or less than 26λ/4, where λ represents oscillation wavelength.

13. The surface-emitting semiconductor laser according to claim 1 ,
wherein the cavity extension region has an optical thickness equal to or less than 12λ/4, where λ represents oscillation wavelength.

14. The surface-emitting semiconductor laser according to claim 3 ,
wherein the carrier block layer has an optical thickness equal to an integral multiple of λ/4, where λ represents oscillation wavelength.

15. The surface-emitting semiconductor laser according to claim 1 ,
wherein the low-refractive-index layer constituting the first semiconductor multilayer reflector is composed of AlAs.

16. A surface-emitting semiconductor laser device comprising:
the surface-emitting semiconductor laser according to claim 1 ; and
an optical element that light emitted by the surface-emitting semiconductor laser enters.

17. An optical transmission device comprising:
the surface-emitting semiconductor laser device according to claim 16 ; and
a transmission unit that transmits a laser beam emitted by the surface-emitting semiconductor laser device via an optical medium.

18. An information processing device comprising:
the surface-emitting semiconductor laser according to claim 1 ;
a light-condensing unit that condenses a laser beam emitted by the surface-emitting semiconductor laser on a recording medium; and
a mechanism that scans the recording medium with the laser beam condensed by the light-condensing unit.

Assignees

• Fuji Xerox Co Ltd

Inventors

• Hayakawa Junichiro
• Murakami Akemi
• Kondo Takashi
• Takeda Kazutaka
• Jogan Naoki
• Sakurai Jun

Classifications

• H01S5/18344

  characterized by the mesa, e.g. dimensions or shape of the mesa · CPC title

• G03G15/04072 Primary

  by laser · CPC title

• H01S5/3054

  p-doping · CPC title

• H04B10/503

  Laser transmitters · CPC title

• H01S5/3432

  the whole junction comprising only (AI)GaAs · CPC title