Laser device integrated with semiconductor optical amplifier on silicon substrate

Patent metadata

Field	Value
Publication number	US-9960567-B2
Application number	US-201414453070-A
Country	US
Kind code	B2
Filing date	Aug 6, 2014
Priority date	Feb 18, 2014
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

A laser device includes a silicon substrate, a buffer layer on the silicon substrate, a laser cavity on the buffer layer including a first active region based on group III-V semiconductor quantum dots, and a semiconductor optical amplifier that is integrated with the laser cavity on the buffer layer, includes a second active region based on group III-V semiconductor quantum dots, and amplifies light emitted from the laser cavity.

First claim

What is claimed is:

1. A laser device comprising:
a silicon substrate;
a buffer layer on the silicon substrate;
a laser cavity on the buffer layer, the laser cavity including a first active region including group III-V semiconductor quantum dots, and a front mirror region and a rear mirror region at both sides of the first active region, the front mirror region and the rear mirror region being spaced apart from each other in a direction parallel to the buffer layer; and
a semiconductor optical amplifier integrated with the laser cavity on the buffer layer and having a second active region including group III-V semiconductor quantum dots, and configured to amplify light emitted from the laser cavity.

2. The laser device of claim 1 , wherein the light generated by the first active region has a wavelength band that is not absorbed by the silicon substrate.

3. The laser device of claim 2 , wherein the light generated by the first active region has a wavelength band equal to or greater than about 1100 nm.

4. The laser device of claim 1 , wherein the buffer layer comprises a group III-V semiconductor material.

5. The laser device of claim 4 , wherein the buffer layer comprises GaAs, InGaAs, InGaP, or GaP.

6. The laser device of claim 1 , further comprising a layer including Ge or SiGe between the silicon substrate and the buffer layer.

7. The laser device of claim 1 , wherein the laser cavity comprises:
a lower clad layer on the buffer layer;
the first active region on the lower clad layer;
an upper clad layer on the first active region; and
the front mirror region and the rear mirror region forming a resonant structure in a direction perpendicular to a direction in which the lower clad layer, the first active region, and the upper clad layer are stacked.

8. The laser device of claim 7 , wherein at least one of the lower clad layer and the upper clad layer comprises a semiconductor material having a bandgap that is greater than a bandgap of the first active region.

9. The laser device of claim 8 , wherein at least one of the lower clad layer and the upper clad layer comprises GaAs, GaP, AlGaAs, InGaP, or InGaAlP.

10. The laser device of claim 8 , further comprising a contact layer on the upper clad layer.

11. The laser device of claim 10 , further comprising:
a first contact metal layer on the contact layer; and
a second contact metal layer on a portion of the lower clad layer, or on a portion of the buffer layer that is exposed by partially etching the contact layer, the upper clad layer, the first active region, and the lower clad layer.

12. The laser device of claim 7 , wherein the lower clad layer and the upper clad layer face the second active region, and
wherein the second active region is between the lower clad layer and the upper clad layer and is optically connected to the front mirror region.

13. The laser device of claim 7 , wherein at least one of the front mirror region and the rear mirror region is embedded between the lower clad layer and the upper clad layer and has a grating structure that repeats in a direction parallel to a surface of the silicon substrate.

14. The laser device of claim 7 , wherein at least one of the front mirror region and the rear mirror region has a distributed Bragg reflector (DBR) structure.

15. The laser device of claim 7 , wherein at least one of the front mirror region and the rear mirror region has a two-dimensional (2D) photonic crystal structure.

16. The laser device of claim 7 , wherein a portion of at least one of the lower clad layer and the upper clad layer that faces the first active region includes an uneven pattern.

17. The laser device of claim 1 , further comprising an anti-reflection coating on a surface through which the light amplified by the semiconductor optical amplifier is emitted.

18. The laser device of claim 1 , further comprising a mirror coating on a surface through which the light amplified by the semiconductor optical amplifier is emitted, the mirror coating forming an extended cavity having a resonant length greater than a resonant length of the laser cavity.

19. The laser device of claim 1 , further comprising an electro-absorption modulator on the silicon substrate optically connected to the semiconductor optical amplifier, the electro-absorption modulator being configured to adjust a wavelength of the light amplified by the semiconductor optical amplifier.

20. The laser device of claim 19 , wherein the electro-absorption modulator comprises a third active region having a bandgap greater than a bandgap of the first active region of the laser cavity.

21. The laser device of claim 20 , wherein the third active region comprises group III-V semiconductor quantum dots.

22. A laser device comprising:
a silicon substrate;
a buffer layer on the silicon substrate;
a laser cavity on the buffer layer, the laser cavity including a first active region including group III-V semiconductor quantum dots;
a semiconductor optical amplifier integrated with the laser cavity on the buffer layer and having a second active region including group III-V semiconductor quantum dots, and configured to amplify light emitted from the laser cavity; and
a grating mirror in the second active region, the grating mirror forming an extended cavity having a resonant length greater than a resonant length of the laser cavity.

23. A laser device comprising:
a silicon substrate;
a buffer layer on the silicon substrate;
a laser cavity on the buffer layer, the laser cavity including a first active region including group III-V semiconductor quantum dots; and
a semiconductor optical amplifier integrated with the laser cavity on the buffer layer and having a second active region including group III-V semiconductor quantum dots, and configured to amplify light emitted from the laser cavity,

wherein the laser cavity comprises a plurality of laser cavities configured to generate light, the plurality of laser cavities having different wavelength bands,
wherein the laser device further comprises:
a plurality of waveguides configured to respectively guide the light emitted from the plurality of laser cavities; and

a coupler configured to couple the light guided by the plurality of waveguides.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Kim Taek

Classifications

• H01S5/021 Primary

  Silicon based substrates · CPC title

• H01S5/0085

  for modulating the output, i.e. the laser beam is modulated outside the laser cavity · CPC title

• H01S5/04257

  having positive and negative electrodes on the same side of the substrate · CPC title

• H01S5/1039

  Details on the cavity length · CPC title

• H01S5/4087

  emitting more than one wavelength · CPC title