Semiconductor laser device

Patent metadata

Field	Value
Publication number	US-9831636-B2
Application number	US-201415123255-A
Country	US
Kind code	B2
Filing date	Sep 4, 2014
Priority date	Mar 13, 2014
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

According to one embodiment of the invention, a semiconductor laser device includes a plurality of first unit stacked bodies and a plurality of second stacked bodies. The plurality of first unit stacked bodies have an emission region including a first quantum well layer and capable of emitting a first infrared light by an intersubband transition, and an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region to a downstream unit stacked body. The plurality of second unit stacked bodies have an emission region including a second quantum well layer and capable of emitting a second infrared light by an intersubband transition, and an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region of the second quantum well layer to a downstream unit stacked body. The second quantum well layer has at least one well width different from a well width of the first quantum well layer. The first unit stacked body and the second stacked body are stacked with spatial periodicity.

First claim

The invention claimed is:

1. A semiconductor laser device comprising:
a plurality of first unit stacked bodies having an emission region including a first quantum well layer and capable of emitting a first infrared light by an intersubband transition, an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region to a downstream unit stacked body, and an adjustment quantum well layer on a downstream of the electron injection region; and
a plurality of second unit stacked bodies having an emission region including a second quantum well layer and capable of emitting a second infrared light by an intersubband transition, an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region of the second quantum well layer to a downstream unit stacked body, and an adjustment quantum well layer on a downstream of the electron injection region, the second quantum well layer having at least one well width different from a well width of the first quantum well layer,
a first unit stacked body and a second unit stacked body being stacked with spatial periodicity, and
an adjustment quantum well layer of a unit stacked body on an upstream creating continuously a transition energy level lower than a mini-band level in an electron injection region on an upstream to an emission region of a unit stacked body adjacent on a downstream at an interface where a first unit stacked body and a second unit stacked body are stacked.

2. The semiconductor laser device according to claim 1 , wherein the adjustment quantum well layer of at least one of the plurality of first unit stacked bodies and the plurality of second unit stacked bodies includes a plurality of pairs of a well layer and a barrier layer having same structure.

3. The semiconductor laser device according to claim 2 , wherein
an electron injection region adjacent to an upstream of the adjustment quantum well layer of the at least one includes a plurality of quantum well layers, and
a width of the well layer and a width of the barrier layer of the adjustment quantum well layer of the at least one are same as a width of a well layer and a width of a barrier layer forming adjacent quantum well layer of the plurality of quantum well layers respectively.

4. A semiconductor laser device comprising:
a plurality of first unit stacked bodies having an emission region including a first quantum well layer and capable of emitting a first infrared light by an intersubband transition, an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region to a downstream unit stacked body, an injection barrier layer injecting an electron into the first quantum well layer and an extracting barrier layer extracting an electron from the first quantum well layer, and
a plurality of second unit stacked bodies having an emission region including a second quantum well layer and capable of emitting a second infrared light by an intersubband transition, an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region of the second quantum well layer to a downstream unit stacked body, an injection barrier layer injecting an electron into the second quantum well layer and an extracting barrier layer extracting an electron from the second quantum well layer, the second quantum well layer having at least one well width different from a well width of the first quantum well layer,
a first unit stacked body and a second unit stacked body being stacked with spatial periodicity.

5. A semiconductor laser device comprising:
a plurality of first unit stacked bodies having an emission region including a first quantum well layer and capable of emitting a first infrared light by an intersubband transition, an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region to a downstream unit stacked body, and an adjustment quantum well layer on a downstream of the electron injection region,
a plurality of second unit stacked bodies having an emission region including a second quantum well layer and capable of emitting a second infrared light by an intersubband transition, an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region of the second quantum well layer to a downstream unit stacked body, and an adjustment quantum well layer on a downstream of the electron injection region, the second quantum well layer having at least one well width different from a well width of the first quantum well layer,
a first unit stacked body and a second unit stacked body being stacked with spatial periodicity
a well width of a well layer determining the intersubband transition in the first quantum well layer being different from a well width of a well layer determining the intersubband transition in the second quantum well layer, and
an adjustment quantum well layer of a unit stacked body on an upstream creates continuously a transition energy level lower than a mini-band level in an electron injection region on an upstream to an emission region of a unit stacked body adjacent on a downstream at an interface where a first unit stacked body and a second unit stacked body are stacked.

6. The semiconductor laser device according to claim 5 , wherein the adjustment quantum well layer of at least one of the plurality of first unit stacked bodies and the plurality of second unit stacked bodies includes a plurality of pairs of a well layer and a barrier layer having same structure.

7. The semiconductor laser device according to claim 6 , wherein
an electron injection region adjacent to an upstream of the adjustment quantum well layer of the at least one includes a plurality of quantum well layers, and
a width of the well layer and a width of the barrier layer of the adjustment quantum well layer of the at least one are same as a width of a well layer and a width of a barrier layer forming adjacent quantum well layer of the plurality of quantum well layers respectively.

8. A semiconductor laser device comprising:
a plurality of first unit stacked bodies having an emission region including a first quantum well layer and capable of emitting a first infrared light by an intersubband transition, and an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region to a downstream unit stacked body;
a plurality of second unit stacked bodies having an emission region including a second quantum well layer and capable of emitting a second infrared light by an intersubband transition, and an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region of the second quantum well layer to a downstream unit stacked body, the second quantum well layer having at least one well width different from a well width of the first quantum well layer, and
a plurality of third unit stacked bodies having an emission region including a third quantum well layer and capable of emitting a third infrared light by an intersubband transition, and an electron injection region capable of transporting an electron relaxed to a mini-band level in the emission region of the third quantum well layer to a downstream unit stacked body, the third quantum well layer having at least one well width different from the well width of the first quantum well layer and the well width of the second quantum well layer,
a first unit stacked body, a second stacked body and the third unit stacked body being stacked with spatial periodicity.

9. The semiconductor laser device according to claim 8 , wher

Assignees

• Toshiba Kk

Inventors

• Yabuhara Hidehiko

Classifications

• G01N21/3504

  for analysing gases, e.g. multi-gas analysis · CPC title

• H01S5/227

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

• H01S5/3402 Primary

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

• H01S5/3408

  characterised by specially shaped wells, e.g. triangular · CPC title

• H01S5/1096

  in a single cavity · CPC title