Method And System For Silicon Photonics Wavelength Division Multiplexing Transceivers

• US 20160119057A1
• Filed: 10/28/2015
• Published: 04/28/2016
• Est. Priority Date: 10/28/2014
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Luxtera Incorporated (Cisco Systems, Inc.)
• Inventors: Mekis, Attila, De Dobbelaere, Peter, Verslegers, Lieven, Sun, Peng, De Koninck, Yannick
• Granted Patent: US 9,912,408 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04B 10/40 Transceivers
• CPC Class Codes: H04B 10/5053 using a parallel, i.e. shunt, combination of modulators
• CPC Class Codes: H04B 10/506 Multiwavelength transmitters
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems

Abstract

Methods and systems for silicon photonics wavelength division multiplexing transceivers are disclosed and may include, in a transceiver integrated in a silicon photonics chip: generating a first modulated output optical signal at a first wavelength utilizing a first electrical signal, generating a second modulated output optical signal at a second wavelength utilizing a second electrical signal, communicating the first and second modulated output optical signals into an optical fiber coupled to the chip utilizing a multiplexing grating coupler in the chip. A received input optical signal may be split into a modulated input optical signal at the first wavelength and a modulated input optical signal at the second wavelength utilizing a demultiplexing grating coupler in the chip. The first and second modulated input optical signals may be converted to first and second electrical input signals utilizing first and second photodetectors in the chip.

Claims

1. A method for optical communication, the method comprising:

in a transceiver integrated in a silicon photonics chip;

generating a first modulated output optical signal at a first wavelength utilizing a first electrical signal;

generating a second modulated output optical signal at a second wavelength utilizing a second electrical signal;

communicating the first and second modulated output optical signals into an optical fiber coupled to the chip utilizing a multiplexing grating coupler in the chip;

splitting a received input optical signal into a modulated input optical signal at the first wavelength and a modulated input optical signal at the second wavelength utilizing a demultiplexing grating coupler in the chip;

converting the modulated input optical signal at the first wavelength to a first electrical input signal utilizing a first photodetector in the chip; and

converting the modulated input optical signal at the second wavelength to a second electrical input signal utilizing a second photodetector in the chip.

2. The method according to claim 1, comprising generating the first and second modulated output optical signals by modulating continuous wave (CW) optical signals at the first and second wavelengths, respectively.

3. The method according to claim 1, wherein the multiplexing grating coupler and/or the demultiplexing grating coupler comprise a grating region and an expanding region between the grating region and an optical waveguide, with a slit between the grating region and the tapered region.

4. The method according to claim 1, wherein the multiplexing grating coupler comprises a pair of intersecting gratings.

5. The method according to claim 4, wherein a spacing of each intersecting grating is configured to scatter optical signals at one of the first and second wavelengths.

6. The method according to claim 4, wherein scatterers are situated at intersections of the intersecting gratings.

7. The method according to claim 6, wherein the scatterers comprise holes in a silicon layer at or near a top surface of the silicon photonics chip.

8. The method according to claim 1, wherein the multiplexing grating coupler and/or the demultiplexing grating coupler comprises a grating with hexagonal symmetry.

9. The method according to claim 1, wherein the demultiplexing grating coupler comprises a grating that scatters optical signals at the first wavelength into at least one waveguide in the silicon photonics chip in a first direction and scatters optical signals at the second wavelength into at least one waveguide in the silicon photonics chip in a second direction substantially opposite to the first direction.

10. The method according to claim 1, wherein the multiplexing grating coupler and/or the demultiplexing grating coupler comprises a beam-splitting grating coupler.

14. The system according to claim 1, wherein a spacing of each intersecting grating is configured to scatter optical signals at one of the first and second wavelengths.

11. A system for communication, the system comprising:

a transceiver integrated in a silicon photonics chip, the transceiver being operable to;

generate a first modulated output optical signal at a first wavelength utilizing a first electrical signal;

generate a second modulated output optical signal at a second wavelength utilizing a second electrical signal;

communicate the modulated output optical signals at the first and second wavelengths into an optical fiber coupled to the chip utilizing a multiplexing grating coupler in the chip;

split a received input optical signal into a modulated input optical signal at the first wavelength and a modulated input optical signal at the second wavelength utilizing a demultiplexing grating coupler in the chip;

convert the modulated input optical signal at the first wavelength to a first electrical input signal utilizing a first photodetector in the chip; and

convert the modulated input optical signal at the second wavelength to a second electrical input signal utilizing a second photodetector in the chip.

12. The system according to claim 11, wherein the transceiver is operable to generate the first and second modulated output optical signals by modulating continuous wave (CW) optical signals at the first and second wavelengths, respectively.

13. The system according to claim 11, wherein the multiplexing grating coupler comprises a pair of intersecting gratings.

15. The system according to claim 13, wherein scatterers are situated at intersections of the intersecting gratings.

16. The system according to claim 15, wherein the scatterers comprise holes in a silicon layer at or near a top surface of the silicon photonics chip.

17. The system according to claim 11, wherein the multiplexing grating coupler and/or the demultiplexing grating coupler comprises a grating with hexagonal symmetry.

18. The system according to claim 11, wherein the demultiplexing grating coupler comprises a grating that scatters optical signals at the first wavelength into a waveguide in the silicon photonics chip in a first direction and scatters optical signals at the second wavelength into a waveguide in the silicon photonics chip in a second direction substantially opposite to the first direction.

19. The system according to claim 11, wherein the multiplexing grating coupler and/or the demultiplexing grating coupler comprises a beam-splitting grating coupler.

20. The system according to claim 11, wherein the multiplexing grating coupler and/or the demultiplexing grating coupler comprise a grating region and an expanding region between the grating region and an optical waveguide, with a slit between the grating region and the tapered region.

21. A system for communication, the system comprising:

a transceiver integrated in a silicon photonics chip, the transceiver being operable to;

generate a plurality of modulated output optical signals at different wavelengths utilizing a plurality of electrical signals; and

communicate the plurality of modulated output optical signals into an optical fiber coupled to the chip utilizing a multiplexing grating coupler in the chip, wherein the multiplexing grating coupler comprises;

an array of scatterers with spacing between the scatterers in different directions corresponding to the different wavelengths; and

expanding regions between the array of scatterers and waveguides coupled to the multiplexing grating coupler.

22. A system for communication, the system comprising:

a transceiver integrated in a silicon photonics chip, the transceiver being operable to;

receive an input optical signal that comprises a plurality of optical signals at different wavelengths from an optical fiber coupled to the chip utilizing a demultiplexing grating coupler in the chip, wherein the demultiplexing grating coupler comprises;

an array of scatterers with spacing between the scatterers in different directions corresponding to the different wavelengths; and

expanding regions between the array of scatterers and waveguides coupled to the demultiplexing grating coupler.