Surface-emitting laser, surface-emitting laser array, laser device, ignitor, internal combustion engine, optical scanner, image forming apparatus, light transmission module, and light emission system

Patent metadata

Field	Value
Publication number	US-10054870-B2
Application number	US-201615364445-A
Country	US
Kind code	B2
Filing date	Nov 30, 2016
Priority date	Dec 11, 2015
Publication date	Aug 21, 2018
Grant date	Aug 21, 2018

Abstract

A surface-emitting laser includes an active layer on which a spacer layer is disposed, and a reflection mirror disposed on the spacer layer, including a current constriction layer that is a selectively-oxidized layer having been selectively oxidized. The current constriction layer is disposed at a position of a node of a standing-wave of an electric field of light oscillated at the active layer and is disposed away from an interface between the spacer layer and the reflection mirror by an optical distance of one-fourth of an oscillation wavelength at the active layer. The selectively-oxidized layer is made of AlGaAs. The reflection mirror includes at least one AlGaInP layer contacting the selectively-oxidized layer.

First claim

What is claimed is:

1. A surface-emitting laser comprising:
an active layer;
a spacer layer disposed on the active layer; and
a reflection mirror disposed on the spacer layer, the reflection mirror including a current constriction layer that is a selectively-oxidized layer made of Al(Ga)As,
the current constriction layer disposed at a position of a node of a standing-wave of an electric field of light oscillated at the active layer and disposed away from an interface between the spacer layer and the reflection mirror by an optical distance of one-fourth of an oscillation wavelength at the active layer,
the reflection mirror including at least one AlGaInP layer that is in direct contact with the selectively-oxidized layer made of Al(Ga)As.

2. The surface-emitting laser according to claim 1 ,
wherein the at least one AlGaInP layer includes two AlGaInP layers,
wherein the selectively-oxidized layer is disposed between the two AlGaInP layers, and
wherein an optical thickness of the selectively-oxidized layer and the two AlGaInP layers is (2n+1)λ/4, where n is a natural number and λ is the oscillation wavelength at the active layer.

3. The surface-emitting laser according to claim 1 ,
wherein the at least one AlGaInP layer is disposed on only one side of the selectively-oxidized layer that faces the active layer.

4. The surface-emitting laser according to claim 1 ,
wherein the selectively-oxidized layer is made of Al x1 Ga 1−x1 As,
wherein Al content x1 satisfies a relation of 0.95≤x1≤1,
wherein the at least one AlGaInP layer is made of (Al x2 Ga 1−x2 As) 0.5 In 0.5 P, and
wherein Al content x2 satisfies a relation of 0.04≤x2≤2.80x1−1.92.

5. The surface-emitting laser according to claim 1 ,
wherein the spacer layer is made of (Al x3 Ga 1−x3 ) 0.5 In 0.5 P,
wherein Al content x3 satisfies a relation of 0≤x3≤0.55, and
wherein a difference in band gap energy between the at least one AlGaInP layer and the spacer layer is greater than or equal to 102 meV.

6. The surface-emitting laser according to claim 1 ,
wherein a valence band discontinuity between the spacer layer and the AlGaInP layer is less than or equal to 134 meV.

7. The surface-emitting laser according to claim 1 ,
wherein a plurality of semiconductor layers is disposed between the active layer and a substrate, and
wherein the substrate is an inclined substrate that is inclined toward any one of a crystal orientation [1 1 1], a crystal orientation [1 −1 −1], a crystal orientation [1 1 −1], and a crystal orientation [1 −1 1] relative to a crystal orientation [1 0 0].

8. A surface-emitting laser array comprising a plurality of surface-emitting lasers, each being the surface-emitting laser according to claim 1 .

9. A laser device comprising:
the surface-emitting laser array according to claim 8 ; and
an optical system to guide a laser beam emitted from the surface-emitting laser array to a target.

10. A laser device comprising:
the surface-emitting laser array according to claim 8 ; and
a condensing optical system to collect and condense a laser beam emitted from the surface-emitting laser array.

11. The laser device according to claim 10 , further comprising a microlens array disposed between the surface-emitting laser array and the condensing optical system.

12. The laser device according to claim 10 , further comprising a light transmission member to transmit light having passed through the condensing optical system.

13. A laser device comprising:
the surface-emitting laser array according to claim 8 ; and
a laser resonator to which a laser beam emitted from the surface-emitting laser array enters.

14. An ignitor comprising:
the laser device according to claim 13 ; and
an optical system to collect and condense a laser beam emitted from the laser device.

15. An internal combustion engine comprising the ignitor according to claim 14 to ignite fuel to generate inflammable gas.

16. An optical scanner comprising:
a scanning light source including the surface-emitting laser according to claim 1 ;
a light deflector to deflect light emitted from the scanning light source; and
a scanning optical system to collect and condense the light deflected by the light deflector.

17. The optical scanner comprising:
a scanning light source including the surface-emitting laser according to claim 8 ;
a light deflector to deflect light emitted from the scanning light source; and
a scanning optical system to collect and condense the light deflected by the light deflector.

18. An image forming apparatus comprising:
an image bearer to bear an image; and
the optical scanner according to claim 16 to scan the image bearer with light modulated according to data of the image.

19. An optical transmitter module comprising:
the surface-emitting laser array according to claim 8 ;
a drive device to drive the surface-emitting laser array to generate a light signal according to an input electrical signal.

20. A light transmission system comprising:
the optical transmitter module according to claim 19 ;
a light transmission medium to transmit a light signal generated by the optical transmitter module; and
a converter to convert the light signal transmitted from the light transmission medium into an electrical signal.

Assignees

• Harada Shinichi
• Jikutani Naoto
• Izumiya Kazuma
• Okura Yusuke
• Ricoh Co Ltd

Inventors

• Harada Shinichi
• Jikutani Naoto
• Izumiya Kazuma
• Okura Yusuke

Classifications

• H01S5/423

  having a vertical cavity · CPC title

• H01S5/34313

  with a well layer having only As as V-compound, e.g. AlGaAs, InGaAs · CPC title

• H01S5/18377

  comprising layers of different kind of materials, e.g. combinations of semiconducting with dielectric or metallic layers · CPC title

• H04N1/06

  using cylindrical picture-bearing surfaces {, i.e. scanning a main-scanning line substantially perpendicular to the axis and lying in a curved cylindrical surface} · CPC title

• H04N1/0284

  in combination with a light integrating, concentrating or diffusing cavity · CPC title