SURFACE EMITTING SEMICONDUCTOR LASER, METHOD FOR FABRICATING SURFACE EMITTING SEMICONDUCTOR LASER, MODULE, LIGHT SOURCE APPARATUS, DATA PROCESSING APPARATUS, LIGHT SENDING APPARATUS, OPTICAL SPATIAL TRANSMISSION APPARATUS, AND OPTICAL SPATIAL TRANSMISSION SYSTEM

• US 20080279229A1
• Filed: 11/28/2007
• Published: 11/13/2008
• Est. Priority Date: 05/11/2007
• Status: Active Grant

• Current Assignee: Fujifilm Business Innovation Corp. (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: Suzuki, Teiichi, Nagao, Daisuki
• Granted Patent: US 7,944,957 B2
• Time in Patent Office: Days
• US Class Current: 372/19
• CPC Class Codes: H01S 2301/18 Semiconductor lasers with special structural design for influencing the near- or far-field
• CPC Class Codes: H01S 5/02251 using optical fibres
• CPC Class Codes: H01S 5/02253 using lenses
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18325 Between active layer and substrate
• CPC Class Codes: H01S 5/18327 Structure being part of a DBR H01S5/18391 takes precedence
• CPC Class Codes: H01S 5/1833 with more than one structure
• CPC Class Codes: H01S 5/18341 Intra-cavity contacts
• CPC Class Codes: H01S 5/18355 having a defined polarisation
• CPC Class Codes: H01S 5/18369 based on dielectric materials
• CPC Class Codes: H01S 5/18397 Plurality of active layers vertically stacked in a cavity for multi-wavelength emission

Abstract

A surface emitting semiconductor laser includes a substrate, a lower reflective mirror formed on the substrate, an active layer formed on the lower reflective mirror, an upper reflective mirror formed on the active layer, an optical mode controlling layer formed between the lower reflective mirror and the upper reflective mirror, and a current confining layer formed between the lower reflective mirror and the upper reflective mirror. The active layer emits light. The upper reflective mirror forms a resonator between the lower reflective mirror and the upper reflective mirror. In the optical mode controlling layer, an opening is formed for selectively absorbing or reflecting off light that is emitted in the active layer. The optical mode controlling layer optically controls mode of laser light. The current confining layer confines current that is applied during driving.

Claims

1. A surface emitting semiconductor laser, comprising:

a substrate;

a lower reflective mirror formed on the substrate;

an active layer formed on the lower reflective mirror, and emitting light;

an upper reflective mirror formed on the active layer, and forming a resonator between the lower reflective mirror and thereof;

an optical mode controlling layer formed between the lower reflective mirror and the upper reflective mirror, and an opening being formed therein for selectively absorbing or reflecting off light that is emitted in the active layer, the optical mode controlling layer optically controlling mode of laser light; and

a current confining layer formed between the lower reflective mirror and the upper reflective mirror, and confining current that is applied during driving.

2. The surface emitting semiconductor laser according to claim 1, wherein a portion of light emitted from the active layer passes through the opening, and rest of the light is absorbed by or reflected off the optical mode controlling layer.

3. The surface emitting semiconductor laser according to claim 1, wherein the optical mode controlling layer is made of a semiconductor layer that has a lattice constant matched to the active layer.

4. The surface emitting semiconductor laser according to claim 1, wherein the optical mode controlling layer comprises a light-absorbing layer.

5. The surface emitting semiconductor laser according to claim 1, wherein the optical mode controlling layer comprises a metal layer.

6. The surface emitting semiconductor laser according to claim 1, wherein the current confining layer comprises a conductive portion and a highly reflective portion that has a higher resistance than the conductive portion does, and the conductive portion is surrounded by the highly reflective portion, and the center of the opening of the optical mode controlling layer coincides with the center of the conductive portion.

7. The surface emitting semiconductor laser according to claim 6, wherein a diameter of the opening of the optical mode controlling layer is smaller than that of the conductive portion of the current confining layer.

8. The surface emitting semiconductor laser according to claim 6, wherein the highly reflective portion of the current confining layer is a selectively oxidized area.

9. The surface emitting semiconductor laser according to claim 1, wherein the lower reflective mirror has a first conductivity type, and the optical mode controlling layer has a second conductivity type, and an electrode is formed between the optical mode controlling layer and the upper reflective mirror, and the electrode is electrically coupled to the optical mode controlling layer.

10. The surface emitting semiconductor laser according to claim 1, wherein the opening of the optical mode controlling layer is formed in a round shape.

11. The surface emitting semiconductor laser according to claim 1, wherein the opening of the optical mode controlling layer is formed to have slit-like shapes.

12. The surface emitting semiconductor laser according to claim 1, wherein the opening of the optical mode controlling layer is formed into plural openings that are asymmetrical with regard to the center of the opening.

13. The surface emitting semiconductor laser according to claim 1, wherein the opening of the optical mode controlling layer is formed into plural openings that are point-symmetric with regard to the center of the opening.

14. The surface emitting semiconductor laser according to claim 1, wherein the diameter of the opening of the optical mode controlling layer is selected in accordance with a wavelength of laser light to be emitted.

15. A method for fabricating a surface emitting semiconductor laser, comprising:

stacking semiconductor layers that include at least a lower reflective mirror, a current confining layer, and an active layer, on a substrate;

forming an optical mode controlling layer that optically controls mode of laser light by forming an opening on the uppermost layer of the stacked semiconductor layers by a photolithography process; and

forming an upper reflective mirror that composes a resonator between the lower reflective mirror and thereof, on the optical mode controlling layer.

16. The method for fabricating a surface emitting semiconductor laser according to claim 15, the method further comprising:

forming a post structure that extends from at least the optical mode controlling layer to the current confining layer, on the substrate; and

forming a conductive portion surrounded by an oxidized area by oxidizing a portion of the current confining layer from a side surface of the post structure.

17. The fabrication method according to claim 15, wherein the lower reflective mirror, the active layer, the current confining layer, and the optical mode controlling layer are formed by epitaxial growth.

18. A module comprising:

a surface emitting semiconductor laser;

an electrical connecting terminal electrically coupled to the surface emitting semiconductor laser; and

an optical component that injects light emitted from the surface emitting semiconductor laser,

the surface emitting semiconductor laser comprising a substrate, a lower reflective mirror formed on the substrate, an active layer formed on the lower reflective mirror and emitting light, an upper reflective mirror formed on the active layer and forming a resonator between the lower reflective mirror and thereof, an optical mode controlling layer formed between the lower reflective mirror and the upper reflective mirror and an opening being formed therein for selectively absorbing or reflecting off light that is emitted in the active layer, the optical mode controlling layer optically controlling mode of laser light, and a current confining layer formed between the lower reflective mirror and the upper reflective mirror and confining current that is applied during driving.

19. A light source apparatus, comprising:

a surface emitting semiconductor laser; and

an irradiating unit that irradiates light emitted from the surface emitting semiconductor laser through an optical component that comprises at least one of a lens or a mirror,

the surface emitting semiconductor laser comprising a substrate, a lower reflective mirror formed on the substrate, an active layer formed on the lower reflective mirror and emitting light, an upper reflective mirror formed on the active layer and forming a resonator between the lower reflective mirror and thereof, an optical mode controlling layer formed between the lower reflective mirror and the upper reflective mirror and an opening being formed therein for selectively absorbing or reflecting off light that is emitted in the active layer, the optical mode controlling layer optically controlling mode of laser light, and a current confining layer formed between the lower reflective mirror and the upper reflective mirror and confining current that is applied during driving.

20. A data processing apparatus, comprising:

a module; and

a sending unit that sends light emitted from a surface emitting semiconductor laser,

the module comprising the surface emitting semiconductor laser, an electrical connecting terminal electrically coupled to the surface emitting semiconductor laser, and an optical component that injects light emitted from the surface emitting semiconductor laser,

the surface emitting semiconductor laser comprising a substrate, a lower reflective mirror formed on the substrate, an active layer formed on the lower reflective mirror and emitting light, an upper reflective mirror formed on the active layer and forming a resonator between the lower reflective mirror and thereof, an optical mode controlling layer formed between the lower reflective mirror and the upper reflective mirror and an opening being formed therein for selectively absorbing or reflecting off light that is emitted in the active layer, the optical mode controlling layer optically controlling mode of laser light, and a current confining layer formed between the lower reflective mirror and the upper reflective mirror and confining current that is applied during driving.

21. A light sending apparatus, comprising:

a module; and

a sending unit that send light emitted from a surface emitting semiconductor laser,

the module comprising the surface emitting semiconductor laser, an electrical connecting terminal electrically coupled to the surface emitting semiconductor laser, and an optical component that injects light emitted from the surface emitting semiconductor laser,

the surface emitting semiconductor laser comprising a substrate, a lower reflective mirror formed on the substrate, an active layer formed on the lower reflective mirror and emitting light, an upper reflective mirror formed on the active layer and forming a resonator between the lower reflective mirror and thereof, an optical mode controlling layer formed between the lower reflective mirror and the upper reflective mirror and an opening being formed therein for selectively absorbing or reflecting off light that is emitted in the active layer, the optical mode controlling layer optically controlling mode of laser light, and a current confining layer formed between the lower reflective mirror and the upper reflective mirror and confining current that is applied during driving.

22. An optical spatial transmission apparatus, comprising:

a module; and

a transmission unit that spatially transmits light emitted from the surface emitting semiconductor laser.

the module comprising the surface emitting semiconductor laser, an electrical connecting terminal electrically coupled to the surface emitting semiconductor laser, and an optical component that injects light emitted from the surface emitting semiconductor laser,

the surface emitting semiconductor laser comprising a substrate, a lower reflective mirror formed on the substrate, an active layer formed on the lower reflective mirror and emitting light, an upper reflective mirror formed on the active layer and forming a resonator between the lower reflective mirror and thereof, an optical mode controlling layer formed between the lower reflective mirror and the upper reflective mirror and an opening being formed therein for selectively absorbing or reflecting off light that is emitted in the active layer, the optical mode controlling layer optically controlling mode of laser light, and a current confining layer formed between the lower reflective mirror and the upper reflective mirror and confining current that is applied during driving.

23. An optical spatial transmission system, comprising:

a module; and

a transmission unit that spatially transmits light emitted from the surface emitting semiconductor laser.

the module comprising the surface emitting semiconductor laser, an electrical connecting terminal electrically coupled to the surface emitting semiconductor laser, and an optical component that injects light emitted from the surface emitting semiconductor laser,

the surface emitting semiconductor laser comprising a substrate, a lower reflective mirror formed on the substrate, an active layer formed on the lower reflective mirror and emitting light, an upper reflective mirror formed on the active layer and forming a resonator between the lower reflective mirror and thereof, an optical mode controlling layer formed between the lower reflective mirror and the upper reflective mirror and an opening being formed therein for selectively absorbing or reflecting off light that is emitted in the active layer, the optical mode controlling layer optically controlling mode of laser light, and a current confining layer formed between the lower reflective mirror and the upper reflective mirror and confining current that is applied during driving.