Tunable laser with directional coupler

Patent metadata

Field	Value
Publication number	US-10297973-B2
Application number	US-201715685866-A
Country	US
Kind code	B2
Filing date	Aug 24, 2017
Priority date	Mar 7, 2014
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A tunable laser has a first mirror, a second mirror, a gain medium, and a directional coupler. The first mirror and the second mirror form an optical resonator. The gain medium and the directional coupler are, at least partially, in an optical path of the optical resonator. The first mirror and the second mirror comprise binary super gratings. Both the first mirror and the second mirror have high reflectivity. The directional coupler provides an output coupler for the tunable laser.

First claim

What is claimed is:

1. A method for coupling silicon waveguides, the method comprising:
guiding light into a first input of a directional coupler, wherein:
the directional coupler has a shoulder;
the directional coupler has a first ridge extending from the first input to a first output disposed on the shoulder; and
the directional coupler has a second ridge extending from a second input to a second output disposed on the shoulder;

guiding light from the first input to the first ridge;
guiding light from the first ridge, through the shoulder to the second ridge, wherein the first ridge tapers to direct at least a portion of light, from the first input, out of the first ridge toward the second ridge; and
guiding light from the second ridge to the second output.

2. The method as recited in claim 1 , wherein the first ridge, the second ridge, and the shoulder are made of silicon.

3. The method as recited in claim 2 , wherein:
the first ridge, the second ridge, and the shoulder are made of crystalline silicon; and
the shoulder is disposed on a silicon substrate.

4. The method as recited in claim 1 , wherein:
the shoulder tapers in a first region;
the first ridge and the second ridge taper in a second region;
the first ridge and the second ridge taper in an opposite direction in a third region than in the second region;
the shoulder tapers in an opposite direction in a fourth region than in the first region;
the second region is between the first region and the third region; and
the third region is between the second region and the fourth region.

5. The method as recited in claim 4 , wherein the shoulder tapers inward from the first input and the second input toward a shoulder waist.

6. The method as recited in claim 4 , wherein:
a width of the first ridge decreases in the second region in a longitudinal direction from the first input to the first output; and
a width of the first ridge increases in the third region in the longitudinal direction from the first input to the first output.

7. The method as recited in claim 1 , wherein a height of the shoulder plus a height of the first ridge is between 0.7 and 4.5 microns.

8. The method of claim 1 , wherein a length measured from the first input to the first output is between 40 and 120 microns.

9. The method of claim 1 , wherein:
the first ridge and the second ridge are separated by a gap; and
the gap has a width between 0.75 to 1.5 microns.

10. The method as recited in claim 1 , wherein:
the first ridge has a minimum width;
the second ridge has a minimum width; and
the minimum width of the first ridge is different from the minimum width of the second ridge.

11. A device for optically coupling waveguides, the device comprising:
a first input;
a second input;
a first output;
a second output;
a shoulder disposed on a substrate;
a first ridge disposed on the shoulder; and
a second ridge disposed on the shoulder, wherein:
the first ridge extends from the first input to the first output,
the second ridge extends from the second input to the second output, and
the first ridge tapers to direct at least a portion of light, from the first input, out of the first ridge toward the second ridge.

12. The device of claim 11 , wherein:
the first ridge and the second ridge are separated by a gap, and
the gap has a width between 0.75 to 1.5 microns.

13. The device of claim 11 , wherein a height of the shoulder plus a height of the first ridge is between 0.7 and 4.5 microns.

14. The device of claim 11 , wherein the device has a length measured from the first input to the first output between 40 and 120 microns.

15. The device of claim 11 , wherein the first ridge, the second ridge, and the shoulder are made of crystalline silicon.

16. The device of claim 11 , wherein a coupler waist is between the first input and the first output, and the shoulder has a narrowing taper toward the coupler waist.

17. The device of claim 11 , further comprising a first mirror and a second mirror, wherein the first input and the first output are optically between the first mirror and the second mirror.

18. A device comprising:
a first mirror;
a second mirror;
an optical coupler between the first mirror and the second mirror, the optical coupler comprising:
a first input;
a second input;
a first output;
a second output;
a shoulder disposed on a substrate;
a first ridge disposed on the shoulder; and
a second ridge disposed on the shoulder, wherein:
the first ridge extends from the first input to the first output,
the second ridge extends from the second input to the second output, and
the first ridge tapers to direct at least a portion of light, from the first input, out of the first ridge toward the second ridge.

19. The device of claim 18 , wherein:
the first ridge and the second ridge are separated by a gap, and
the gap has a width between 0.75 to 1.5 microns.

20. The device of claim 18 , wherein the optical coupler has a length measured from the first input to the first output between 40 and 120 microns.

Assignees

• Skorpios Tech Inc

Inventors

• Chaouch Hacene
• Li Guoliang

Classifications

• H01S5/1218

  in superstructured configuration, e.g. more than one period in an alternate sequence · CPC title

• G02B2006/12097

  Ridge, rib or the like · CPC title

• H01S5/021

  Silicon based substrates · CPC title

• H01S3/0675

  Resonators including a grating structure, e.g. distributed Bragg reflectors [DBR] or distributed feedback [DFB] fibre lasers · CPC title

• H01S5/0683

  by monitoring the optical output parameters · CPC title