Granted Patent B2

US 9,240,673 · App. 14/601,101 · Granted Jan 19, 2016

Abstract

Claims (68)

1. A wavelength tunable silicon-on-insulator (SOI) laser comprising:

a laser cavity including:

a semiconductor gain medium having a front end and a back end; and

a phase-tunable waveguide platform coupled to the front end of the semiconductor gain medium;

wherein the phase-tunable waveguide platform includes:

a first Distributed Bragg Reflector (DBR);

a first transition region on a first side of the first DBR;

a second transition region on a second side of the first DBR; and

a second Distributed Bragg Reflector (DBR);

at least one of the Distributed Bragg Reflectors having a comb reflectance spectrum;

wherein a highly reflective mirror is located at the back end of the semiconductor gain medium forming a mirror of the laser cavity such that the gain medium functions as a reflective semiconductor optical amplifier (RSOA);

wherein at the first transition region a waveguide of a first height and a first width is coupled to a waveguide of a second height and a second width, the first height being different from the second height and/or the first width being different from the second width;

wherein at the second transition region a waveguide of the second height and the second width is coupled to a waveguide of a third height and a third width, the second height being different from the third height and/or the second width being different from the third width; and

wherein the second transition region forms the output of the laser.

2. The wavelength tunable laser of claim 1 , wherein the Distributed Bragg Reflector having a comb reflectance spectrum is a Sectioned Grating Distributed Bragg Reflector (SGDBR).

3. The wavelength tunable laser of claim 1 , wherein at least one of the first Distributed Bragg Reflector and the second Distributed Bragg Reflector is a phase-tunable Distributed Bragg Reflector.

4. The wavelength tunable laser of claim 3 , wherein the phase-tunable Distributed Bragg Reflector includes a phase tuning region which comprises an electro-optical medium.

5. The wavelength tunable laser of claim 3 , wherein the phase-tunable Distributed Bragg Reflector comprises a phase tuning region which includes a p-i-n junction region.

6. The wavelength tunable laser of claim 3 , wherein the phase-tunable Distributed Bragg Reflector comprises a phase tuning region which includes a p-n junction region.

7. The wavelength tunable laser of claim 1 , wherein both of the first Distributed Bragg Reflector and the second Distributed Bragg Reflector are phase-tunable Distributed Bragg Reflectors.

8. The wavelength tunable laser of claim 7 ,

wherein the phase tuning region of the first Distributed Bragg Reflector includes any one of: a p-n junction; p-i-n junction; and

wherein the phase tuning region of the second Distributed Bragg Reflector includes any one of: a p-n junction, p-i-n junction.

9. The wavelength tunable laser of claim 1 , wherein:

the first Distributed Bragg Reflector is a Sectioned Grating-Distributed Bragg reflector (SG-DBR); and

the second Distributed Bragg Reflector is a Sectioned Grating-Distributed Bragg reflector (SG-DBR).

10. The wavelength tunable laser of claim 1 , wherein the phase-tunable waveguide platform includes bifurcated waveguides, each arm of the bifurcated waveguides comprising one Distributed Bragg Reflector.

11. The wavelength tunable laser of claim 10 , wherein the phase-tunable waveguide platform includes an MMI coupler which couples light to the bifurcated waveguides.

12. The wavelength tunable laser of claim 1 , wherein:

the first Distributed Bragg Reflector is a Sectioned Grating-Distributed Bragg reflector (SG-DBR); and

the second Distributed Bragg Reflector is a Digital Supermode-Distributed Bragg Reflector (DS-DBR).

13. The wavelength tunable laser of claim 1 , further comprising at least one phase tuning region which is separate from the first and second Distributed Bragg Reflectors.

14. The wavelength tunable laser of claim 13 , wherein one or more of said phase tuning region(s) comprise(s) an electro-optical medium.

15. The wavelength tunable laser of claim 13 , wherein one or more of said phase tuning region(s) include(s): a p-n junction or a p-i-n junction.

16. The wavelength tunable laser of claim 1 , wherein the waveguide platform comprises a waveguide portion having a silicon overlayer thickness (T) of more than or equal to 1 μm and less than or equal to 4 μm.

17. The wavelength tunable laser of claim 16 , wherein the waveguide platform comprises a waveguide portion having a silicon overlayer thickness (T) of more than or equal to 2.5 μm and less than or equal to 3.2 μm.

18. The wavelength tunable laser of claim 1 , wherein the semiconductor gain medium is a gain chip.

19. The wavelength tunable laser of claim 1 , wherein said mirror located at the back end of the semiconductor gain medium is a reflective back-facet of the semiconductor gain medium.

20. The wavelength tunable laser of claim 1 , wherein the second height is less than the first height.

21. The wavelength tunable laser of claim 1 , wherein the first and second Distributed Bragg Reflectors are located in a waveguide of the second height.

22. The wavelength tunable laser of claim 1 , wherein the second width is less than the first width.

23. The wavelength tunable laser of claim 22 , wherein the first and second Distributed Bragg Reflectors are located in a waveguide of said second width.

24. The wavelength tunable laser of claim 1 , wherein the first transition region includes a taper.

25. The wavelength tunable laser of claim 1 , wherein the first transition region is a mode transformer.

26. The wavelength tunable laser of claim 1 , wherein the mirror of the laser cavity which is located at the back end of the semiconductor gain medium has a reflectivity of at least 85%.

27. The wavelength tunable laser of claim 1 , wherein the mirror of the laser cavity which is located at the back end of the semiconductor gain medium has a reflectivity of at least 90%.

28. A wavelength tunable silicon-on-insulator (SOI) laser comprising:

a laser cavity including:

a semiconductor gain medium having a front end and a back end; and

a phase-tunable waveguide platform coupled to the front end of the semiconductor gain medium;

wherein the phase-tunable waveguide platform includes:

a first Distributed Bragg Reflector (DBR);

a first transition region on a first side of the first DBR;

a second transition region on a second side of the first DBR; and

a second Distributed Bragg Reflector (DBR);

at least one of the Distributed Bragg Reflectors having a comb reflectance spectrum;

wherein at the first transition region a waveguide of a first height and a first width is coupled to a waveguide of a second height and a second width, the first height being different from the second height and/or the first width being different from the second width;

wherein at the second transition region a waveguide of a third height and a third width is coupled to a waveguide of a fourth height and a fourth width, the third height being different from the fourth height and/or the third width being different from the fourth width; and

wherein a mirror having a reflectivity of at least 85% is located at the back end of the semiconductor gain medium to form a mirror of the laser cavity such that the gain medium functions as a reflective semiconductor optical amplifier (RSOA).

29. A wavelength tunable silicon-on-insulator (SOI) laser comprising:

a laser cavity including:

a semiconductor gain medium having a front end and a back end; and

a phase-tunable waveguide platform coupled to the front end of the semiconductor gain medium;

wherein the phase-tunable waveguide platform includes a first Distributed Bragg Reflector (DBR) and a second Distributed Bragg Reflector (DBR); at least one of the Distributed Bragg Reflectors having a comb reflectance spectrum;

wherein a highly reflective mirror is located at the back end of the semiconductor gain medium forming a mirror of the laser cavity such that the gain medium functions as a reflective semiconductor optical amplifier (RSOA);

wherein one of the first DBR and the second DBR forms the output of the laser;

wherein the first DBR is located in a waveguide having a ridge and comprising a p-i-n junction; and

wherein a p-doped region of the junction and an n-doped region of the junction overlap respective side walls of the waveguide ridge and an intrinsic region of the junction occupies only a central portion of the waveguide ridge.

Assignments (11)