Surface emitting semiconductor laser and process for producing the same

• US 6,898,226 B2
• Filed: 12/10/2002
• Issued: 05/24/2005
• Est. Priority Date: 12/19/2001
• Status: Expired due to Term

• Current Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: Sakurai, Jun, Otoma, Hiromi
• Primary Examiner(s): Harvey, Minsun Oh
• Assistant Examiner(s): Nguyen, Tuan N.
• Application Number:
  US10/315,152
• Publication Number:
  US 20030169795A1
• Time in Patent Office: 896 Days
• Field of Search: 372/75, 372 43- 50
• US Class Current: 372/46.01
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01S 2301/173 The laser chip comprising special buffer layers, e.g. dislocation prevention or reduction
• CPC Class Codes: H01S 2301/176 Specific passivation layers on surfaces other than the emission facet
• CPC Class Codes: H01S 5/18311 using selective oxidation
• CPC Class Codes: H01S 5/18347 Mesa comprising active layer
• CPC Class Codes: H01S 5/18358 containing spacer layers to adjust the phase of the light wave in the cavity
• CPC Class Codes: H01S 5/3054 p-doping
• CPC Class Codes: H01S 5/3432 the whole junction comprising only (AI)GaAs
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

A surface emitting semiconductor laser includes a substrate, a first semiconductor multilayer reflector formed on the substrate, an active region formed on the first semiconductor multilayer reflector, a second semiconductor multilayer reflector formed on the active region, a current confinement layer interposed between the first and second semiconductor multilayer reflectors and partially including an oxide region, and an insulating layer formed on a coated surface provided by a semiconductor layer which is part of the first semiconductor multilayer reflector and is revealed after removal of a surface oxidation layer.

Claims

1. A surface emitting semiconductor laser comprising:

a substrate;

a first semiconductor multilayer reflector formed on the substrate;

an active region formed on the first semiconductor multilayer reflector;

a second semiconductor multilayer reflector formed on the active region;

a current confinement layer interposed between the first and second semiconductor multilayer reflectors and partially including an oxide region; and

an insulating layer formed on a coated surface provided by at least one semiconductor layer which is part of the first semiconductor multilayer reflector and is revealed after removal of a surface oxidation layer, said at least one semiconductor layer having an Al composition equal to or smaller than 50%.

2. The surface emitting semiconductor layer according to claim 1, wherein:

the first semiconductor multilayer reflector is a distributed Bragg reflector composed of alternatively laminating semiconductor layers having different Al compositions.

3. The surface emitting semiconductor laser according to claim 1, wherein the distributed Bragg reflector comprises one of Al_xGa₁₋

xAs and Al_xGa_1-xN.

4. The surface emitting semiconductor laser according to claim 1, wherein the semiconductor layer of the first multilayer reflector is thicker than other semiconductor layers thereof.

5. The surface emitting semiconductor laser according to claim 4, wherein the semiconductor layer comprises a region that has an optical thickness defined by a product of n and d, the product being equal to an odd-number multiple of a length equal to ¼

of a wavelength of laser oscillation where d denotes a thickness of the semiconductor layer, and n denotes a refractive index thereof.

6. The surface emitting semiconductor laser according to claim 1, wherein the active region comprises a multiquantum well structure and spacer layers on both sides thereof.

7. The surface emitting semiconductor laser according to claim 1, wherein the surface oxidation layer has been removed by dry etching.

8. A surface emitting semiconductor laser comprising:

a substrate;

semiconductor layers laminated on the substrate in turn, the semiconductor layers includes a first reflector having a first electrical conduction type, an active region on the first reflector, at least one current confinement partially including an oxide region, and a second reflector having a second electrical conduction type;

a mesa at least extending from the second reflector to the current confinement region,

a bottom of the mesa having a coated surface that is provided by at least one semiconductor layer having an Al composition equal to or smaller than 50% and is revealed after removal of a surface oxidation layer, an insulating film being provided on the coated surface.

9. The surface emitting semiconductor laser according to claim 8, wherein the insulating layer covers at least a sidewall and the bottom of the mesa.

10. A surface emitting semiconductor laser comprising:

a substrate;

a first semiconductor multilayer reflector formed on the substrate;

an active region formed on the first semiconductor multilayer reflector;

a pair of spacer layers that sandwich the active layer;

a second semiconductor multilayer reflector formed on the active region;

a current confinement layer interposed between the first and second semiconductor multilayer reflectors and partially including an oxide region, a mesa structure ranging at least from the second semiconductor multilayer reflector to the current confinement layer being defined; and

a bottom of the mesa structure having at least a first one of the pair of spacer layers that is in the absence of an oxide layer and has an Al composition equal to or smaller than 50%.

11. The surface emitting semiconductor laser according to claim 10, further comprising an insulating layer covering at least a sidewall and the bottom of the mesa structure.