TWO DIMENSIONAL PHOTONIC CRYSTAL SURFACE EMITTING LASER

• US 20110134941A1
• Filed: 12/01/2010
• Published: 06/09/2011
• Est. Priority Date: 12/09/2009
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Hoshino, Katsuyuki, Nagatomo, Yasuhiro
• Granted Patent: US 8,130,808 B2
• Time in Patent Office: Days
• US Class Current: 372/7
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01S 2304/12 Pendeo epitaxial lateral overgrowth [ELOG], e.g. for growing GaN based blue laser diodes
• CPC Class Codes: H01S 5/11 Comprising a photonic bandgap structure
• CPC Class Codes: H01S 5/187 using Bragg reflection
• CPC Class Codes: H01S 5/2031 characterized by special waveguide layers, e.g. asymmetric waveguide layers or defined bandgap discontinuities
• CPC Class Codes: H01S 5/2231 with inner confining structure only between the active layer and the upper electrode
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

Provided is a two dimensional photonic crystal surface emitting laser which can suppress light leaking outside in an in-plane direction of the two dimensional photonic crystal and an absorption loss in an active layer caused by serving as an absorbing layer without contributing to light emission, and can improve light use efficiency. The surface emitting laser has a laminated structure in which an active layer and a photonic crystal layer are laminated in a vertical direction, has a resonance mode in an in-plane direction of the photonic crystal, and extracts light in a vertical direction to a surface of the photonic crystal, wherein the laminated structure has a multi-refractive index layer including a central region made of a high refractive index medium and a peripheral portion made of a low refractive index medium with a lower refractive index than that of the high refractive index medium.

Claims

1. A two dimensional photonic crystal surface emitting laser having a laminated structure in which an active layer and a photonic crystal layer having a structure of a photonic crystal are laminated on a substrate,

having a resonance mode in an in-plane direction of the photonic crystal, and extracting light in a vertical direction to a surface of the photonic crystal, wherein

the laminated structure has a multi-refractive index layer including a central region made of a high refractive index medium and a peripheral portion made of a low refractive index medium with a lower refractive index than that of the high refractive index medium.

2. The two dimensional photonic crystal surface emitting laser according to claim 1, wherein an electrode for injecting a carrier in the active layer is provided in a central region of a surface of the laminated structure.

3. The two dimensional photonic crystal surface emitting laser according to claim 2, wherein a peripheral portion made of a low refractive index medium in the multi-refractive index layer is formed in a region not overlapped with the electrode.

4. The two dimensional photonic crystal surface emitting laser according to claim 1, wherein the multi-refractive index layer is formed between the photonic crystal layer and the active layer.

5. The two dimensional photonic crystal surface emitting laser according to claim 1, wherein the multi-refractive index layer is formed on an opposite side of the two dimensional photonic crystal with the active layer sandwiched therebetween.

6. The two dimensional photonic crystal surface emitting laser according to claim 2, wherein the electrode is a p-type electrode.

7. The two dimensional photonic crystal surface emitting laser according to claim 1, wherein a peripheral portion made of a low refractive index medium in the multi-refractive index layer has such a layer configuration that a layer thickness becomes gradually thicker from the central region side to an outer peripheral portion side.

8. The two dimensional photonic crystal surface emitting laser according to claim 1, wherein a peripheral portion made of a low refractive index medium in the multi-refractive index layer has such a layer configuration that a refractive index thereof becomes gradually lower from the central region side to an outer peripheral portion side.

9. The two dimensional photonic crystal surface emitting laser according to claim 1, wherein a low refractive index medium in the multi-refractive index layer is made of an insulation medium.

10. The two dimensional photonic crystal surface emitting laser according to claim 1, wherein the photonic crystal layer is made of a nitride semiconductor.