End-face-emitting photonic crystal laser element

• US 9,130,339 B2
• Filed: 08/31/2012
• Issued: 09/08/2015
• Est. Priority Date: 09/30/2011
• Status: Active Grant

• Current Assignee: Hamamatsu Photonics KK, Kyoto University
• Original Assignee: Hamamatsu Photonics KK, Kyoto University
• Inventors: Noda, Susumu, Kurosaka, Yoshitaka, Watanabe, Akiyoshi, Hirose, Kazuyoshi, Sugiyama, Takahiro
• Primary Examiner(s): Matthews, Colleen A
• Assistant Examiner(s): Vu, Vu A
• Application Number:
  US14/347,780
• Publication Number:
  US 20140247852A1
• Time in Patent Office: 1,103 Days
• Field of Search: 372/45.013, 372/102, 372/105
• US Class Current: 1/1
• CPC Class Codes: H01S 5/0421 characterised by the semiconducting contacting layers electrodes H01S5/0425
• CPC Class Codes: H01S 5/04256 characterised by the configuration
• CPC Class Codes: H01S 5/0653 Mode suppression, e.g. specific multimode
• CPC Class Codes: H01S 5/11 Comprising a photonic bandgap structure
• CPC Class Codes: H01S 5/1203 over only a part of the length of the active region
• CPC Class Codes: H01S 5/34313 with a well layer having only As as V-compound, e.g. AlGaAs, InGaAs
• CPC Class Codes: H01S 5/34353 based on (AI)GaAs

Abstract

When an end-face-emitting photonic crystal laser element 10 is seen in an X axis, one end of an upper electrode E2 overlaps a laser light exit surface SF, the upper electrode E2 and an opposite end face SB are separated from each other, the upper electrode E2 is separated from both lateral end faces SR, SL, and one end of an active layer 3B overlaps the laser light exit surface SF.

Claims

1. An end-face-emitting photonic crystal laser element comprising:

a lower cladding layer comprised of a semiconductor;

an upper cladding layer comprised of a semiconductor;

an active layer including a quantum well layer disposed between the lower and upper cladding layers, the quantum well layer having a plurality of barrier layers and a well layer located between the barrier layers, the barrier layers having an energy band gap smaller than that of any of the lower and upper cladding layers;

a diffraction grating layer having a region disposed between at least one of the lower and upper cladding layers and the active layer;

a lower electrode disposed on a surface of the lower cladding layer; and

an upper electrode disposed on a surface of the upper cladding layer, wherein a shape of the upper electrode is substantially a square or a circle;

wherein, in an XYZ orthogonal coordinate system with X, Y, and Z axes respectively lying in thickness, width, and length directions of the element, the end-face-emitting photonic crystal laser element has a laser light exit surface along an XY plane;

wherein the end-face-emitting photonic crystal laser element has four end faces surrounding the X axis;

wherein one of the end faces is the laser light exit surface, each of the others being displaced from the active layer more than 50 μ

m in a YZ plane; and

wherein, when referring to the surface opposing the laser light exit surface in the end faces as an opposite end face and the remaining pair of end faces as lateral end faces and seeing in the X axis, one end of the upper electrode overlaps the laser light exit surface, the upper electrode and the opposite end face are separated from each other, the upper electrode is separated from both of the lateral end faces, and one end of the active layer overlaps the laser light exit surface.

2. An end-face-emitting photonic crystal laser element according to claim 1,

wherein, when seen in the X axis, the active layer and the opposite end face are separated from each other, the active layer is separated from both of the lateral end faces, and the active layer is in contact with a semiconductor material having a wider energy bandgap than that of the well layer except for the laser light exit surface within a YZ plane including the active layer.

3. An end-face-emitting photonic crystal laser element according to claim 2, wherein the semiconductor material has an energy bandgap wider than that corresponding to the laser resonance wavelength along the Z axis in the active layer.

4. An end-face-emitting photonic crystal laser element according to claim 2, wherein the diffraction grating layer comprises:

a base layer comprised of the semiconductor material; and

a plurality of different refractive index parts, located periodically within the base layer, having a refractive index different from that of the base layer; and

wherein the base layer is in contact with the active layer within the YZ plane including the active layer.

5. An end-face-emitting photonic crystal laser element according to claim 3, wherein the diffraction grating layer comprises:

a base layer comprised of the semiconductor material; and

a plurality of different refractive index parts, located periodically within the base layer, having a refractive index different from that of the base layer; and

wherein the base layer is in contact with the active layer within the YZ plane including the active layer.