Quantum cascade semiconductor laser

Patent metadata

Field	Value
Publication number	US-2016294159-A1
Application number	US-201615088490-A
Country	US
Kind code	A1
Filing date	Apr 1, 2016
Priority date	Apr 3, 2015
Publication date	Oct 6, 2016
Grant date	—

Abstract

A quantum cascade semiconductor laser includes a substrate with a main surface including a waveguide area and a distributed Bragg reflection area that are arranged in a direction of a first axis; a laser region provided on the waveguide area, the laser region including a mesa waveguide having first and second side surfaces, and first and second burying regions provided on the first and second side surfaces, respectively; a distributed Bragg reflection region provided on the distributed Bragg reflection area, the distributed Bragg reflection region including a semiconductor wall having first bulk semiconductor regions and first laminate regions that are alternately arrayed in a direction of a second axis intersecting the first axis; and an upper electrode provided on the laser region. Each first bulk semiconductor region includes a bulk semiconductor layer. Each first laminate region includes a stacked semiconductor layer having a plurality of semiconductor layers.

First claim

What is claimed is:

1 . A quantum cascade semiconductor laser comprising:
a substrate with a main surface including a waveguide area and a distributed Bragg reflection area that are arranged in a direction of a first axis; a laser region provided on the waveguide area of the substrate, the laser region including a mesa waveguide having a first side surface and a second side surface, a first burying region provided on the first side surface and the main surface of the substrate, and a second burying region provided on the second side surface and the main surface of the substrate, the first and second side surfaces of the mesa waveguide extending in the direction of the first axis; a distributed Bragg reflection region provided on the distributed Bragg reflection area of the substrate, the distributed Bragg reflection region including a semiconductor wall extending in a direction of a normal axis perpendicular to the main surface of the substrate, the semiconductor wall including a plurality of first bulk semiconductor regions and a plurality of first laminate regions that are alternately arrayed in a direction of a second axis intersecting the first axis and the normal axis; and an upper electrode provided on the laser region, the upper electrode being in contact with a top surface of the mesa waveguide, wherein each of the first bulk semiconductor regions includes a bulk semiconductor layer, and each of the first laminate regions includes a stacked semiconductor layer having a plurality of semiconductor layers.

2 . The quantum cascade semiconductor laser according to claim 1 ,
wherein the mesa waveguide includes a core layer and an upper cladding layer disposed on the core layer, and the stacked semiconductor layer of the first laminate region includes the core layer and the upper cladding layer.

3 . The quantum cascade semiconductor laser according to claim 1 ,
wherein each of the first and second burying regions includes a plurality of second bulk semiconductor regions and a plurality of second laminate regions that are alternately arrayed in the direction of the second axis, and each of the second laminate regions includes the stacked semiconductor layer.

4 . The quantum cascade semiconductor laser according to claim 3 ,
wherein each of the first and second burying regions includes a first burying portion and a second burying portion that are arranged along the direction of the second axis in order from a waveguide axis toward a side surface of the quantum cascade semiconductor laser, the first burying portion includes the second laminate regions and the second bulk semiconductor regions that are alternately arrayed in the direction of the second axis, and the second burying portion does not include the second laminate regions and includes the second bulk semiconductor regions extending in the direction of the second axis.

5 . The quantum cascade semiconductor laser according to claim 3 ,
wherein the second bulk semiconductor regions include an undoped or semi-insulating semiconductor.

6 . The quantum cascade semiconductor laser according to claim 1 , further comprising a first semiconductor capping layer provided on the first bulk semiconductor regions in the semiconductor wall,
wherein the first semiconductor capping layer is in contact with the first bulk semiconductor regions of the semiconductor wall, and the first semiconductor capping layer is made of the same material as that of the first bulk semiconductor regions.

7 . The quantum cascade semiconductor laser according to claim 1 ,
wherein the semiconductor wall includes a first portion and a second portion that are arranged along a direction of the second axis in order from a waveguide axis toward a side surface of the quantum cascade semiconductor laser, the first portion includes the first laminate regions and the first bulk semiconductor regions that are alternately arrayed in the direction of the second axis, and the second portion does not include the first laminate regions and includes the first bulk semiconductor regions.

8 . The quantum cascade semiconductor laser according to claim 1 , further comprising an insulating film made of a dielectric material, the insulating film being provided between the upper electrode and the first and second burying regions.

9 . The quantum cascade semiconductor laser according to claim 1 , further comprising a second semiconductor capping layer made of an undoped semiconductor or a semi-insulating semiconductor, the second semiconductor capping layer being provided between the upper electrode and the first and second burying regions.

10 . The quantum cascade semiconductor laser according to claim 1 , further comprising a first reinforcing section connecting a first wall and a second wall among the semiconductor walls with each other.

11 . The quantum cascade semiconductor laser according to claim 10 ,
wherein the first wall includes a third portion that is connected to the first reinforcing section, the second wall includes a fourth portion that is connected to the first reinforcing section, and the first reinforcing section, the third portion and the fourth portion are made of the same material.

12 . The quantum cascade semiconductor laser according to claim 1 , further comprising a second reinforcing section connecting each of the first and second burying regions to the corresponding semiconductor wall.

13 . The quantum cascade semiconductor laser according to claim 12 ,
wherein the semiconductor wall includes a connecting section that is connected to the second reinforcing section, and the second reinforcing section and the connecting section of the semiconductor wall are made of the same material.

14 . The quantum cascade semiconductor laser according to claim 12 ,
wherein the first burying region includes a third burying portion that is connected to the second reinforcing section, the second burying region includes a fourth burying portion that is connected to the second reinforcing section, and the second reinforcing section, the third burying portion, and the fourth burying portion are made of the same material.

15 . The quantum cascade semiconductor laser according to claim 1 ,
wherein the semiconductor wall has a length shorter than a width of the substrate in the direction of the second axis.

Assignees

• Sumitomo Electric Industries

Inventors

• Hashimoto Jun-Ichi

Classifications

• H01S5/227 Primary

  Buried mesa structure {; Striped active layer} · CPC title

• H01S5/3402 Primary

  intersubband lasers, e.g. transitions within the conduction or valence bands · CPC title

• H01S5/0234

  Up-side down mountings, e.g. Flip-chip, epi-side down mountings or junction down mountings · CPC title

• H01S5/02461

  Structure or details of the laser chip to manipulate the heat flow, e.g. passive layers in the chip with a low heat conductivity · CPC title

• H01S5/2275

  mesa created by etching · CPC title