Method and system for integrated power combiners

• US 8,625,935 B2
• Filed: 06/10/2011
• Issued: 01/07/2014
• Est. Priority Date: 06/15/2010
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Luxtera Incorporated (Cisco Systems, Inc.)
• Inventors: Mekis, Attila, Narasimha, Adithyaram, Witzens, Jeremy
• Primary Examiner(s): PEACE, RHONDA S
• Application Number:
  US13/157,642
• Publication Number:
  US 20110305414A1
• Time in Patent Office: 942 Days
• Field of Search: 385/3
• US Class Current: 385/3
• CPC Class Codes: G02B 2006/12142 Modulator
• CPC Class Codes: G02B 6/125 Bends, branchings or intersections
• CPC Class Codes: G02B 6/126 using polarisation effects G02B6/1226 takes precedence
• CPC Class Codes: G02B 6/2726 in or on light guides, e.g. polarisation means assembled in a light guide
• CPC Class Codes: G02B 6/2773 Polarisation splitting or combining
• CPC Class Codes: G02B 6/29344 operating by modal interference or beating, i.e. of transverse modes, e.g. zero-gap directional coupler, MMI
• CPC Class Codes: G02B 6/34 utilising prism or grating G02B6/293 takes precedence
• CPC Class Codes: G02B 6/4286 Optical modules with optical power monitoring
• CPC Class Codes: G02F 1/011 in optical waveguides, not otherwise provided for in this subclass
• CPC Class Codes: G02F 1/0136 for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation G02F1/0353 takes precedence
• CPC Class Codes: G02F 1/313 in an optical waveguide structure

Abstract

A system for integrated power combiners is disclosed and may include receiving optical signals in input optical waveguides and phase-modulating the signals to configure a phase offset between signals received at a first optical coupler, where the first optical coupler may generate output signals having substantially equal optical powers. Output signals of the first optical coupler may be phase-modulated to configure a phase offset between signals received at a second optical coupler, which may generate an output signal having an optical power of essentially zero and a second output signal having a maximized optical power. Optical signals received by the input optical waveguides may be generated utilizing a polarization-splitting grating coupler to enable polarization-insensitive combining of optical signals. Optical power may be monitored using optical detectors. The monitoring of optical power may be used to determine a desired phase offset between the signals received at the first optical coupler.

Claims

1. A system for processing optical signals, the system comprising:

a chip comprising an optical power combiner, said optical power combiner comprising input optical waveguides, optical couplers, and output optical waveguides, said chip being operable to;

receive optical signals in each of said input optical waveguides;

phase-modulate one or both received optical signals to configure a phase offset between signals received at a first optical coupler, wherein said first optical coupler generates output signals having substantially equal optical powers; and

phase-modulate one or both output signals of said first optical coupler to configure a phase offset between signals received at a second optical coupler, wherein said second optical coupler generates an output signal in a first of said output optical waveguides having an optical power of essentially zero and an output signal in a second of said output optical waveguides having a maximized optical power.

2. The system according to claim 1, wherein said optical couplers comprise grating couplers.

3. The system according to claim 1, wherein said optical couplers comprise multi-mode interference couplers.

4. The system according to claim 1, wherein said optical couplers comprise multi-stage cascaded directional couplers.

5. The system according to claim 1, wherein said chip comprises a CMOS chip.

6. The system according to claim 1, wherein said chip is operable to generate said optical signals received by said input optical waveguides utilizing a polarization-splitting grating coupler.

7. The system according to claim 6, wherein said polarization splitting grating coupler enables polarization-insensitive combining of optical signals utilizing said optical power combiner.

8. The system according to claim 1, wherein said chip is operable to monitor optical power in waveguides coupling said optical couplers using optical detectors, wherein said monitoring of optical power is used to determine a desired phase offset between said signals received at said first optical coupler.

9. The system according to claim 8, wherein said chip is operable to communicate optical signals to said optical detectors utilizing optical taps in said coupling waveguides.

10. The system according to claim 1, wherein said optical power combiner comprises a plurality of stages.

11. The system according to claim 1, wherein said optical power combiner is operable to receive an optical source signal in to said chip via optical fibers.

12. A method for processing signals, the method comprising:

in a chip comprising a polarization controller, said polarization controller comprising an input optical waveguide, optical couplers, and a polarization-splitting grating coupler;

generating two output signals from a first optical coupler that receives an input signal from said input optical waveguide;

phase modulating one or both of said two output signals to configure a phase offset between said two generated output signals before communicating signals with said phase offset to a second optical coupler;

phase modulating one or both optical signals generated by said second optical coupler to configure a phase offset between signals communicated to said polarization-splitting grating coupler; and

launching an optical signal of a desired polarization into an optical fiber via said polarization-splitting grating coupler by combining said signals communicated to said polarization-splitting grating coupler.

13. The method according to claim 12, wherein said optical couplers comprise one or more of grating couplers, multi-mode interference couplers, and multi-stage cascaded directional couplers.

14. The method according to claim 12, wherein said chip comprises a CMOS chip.

15. The method according to claim 12, comprising generating said optical signals received by said input optical waveguides utilizing a polarization-splitting grating coupler.

16. The method according to claim 15, comprising polarization-insensitive combining of optical signals utilizing said polarization splitting grating coupler.

17. The method according to claim 12, comprising monitoring optical power in waveguides coupling said optical couplers using optical detectors, wherein said monitoring of optical power is used to determine a desired phase offset between said signals received at said first optical coupler.

18. The method according to claim 17, comprising communicating optical signals to said optical detectors utilizing optical taps in said coupling waveguides.

19. The method according to claim 12, wherein said optical power combiner comprises a plurality of stages.

20. The method according to claim 12, comprising receiving an optical source signal in to said chip via optical fibers.

21. A system for processing signals, the system comprising:

a CMOS photonics chip comprising an optical power combiner, said optical power combiner comprising input optical waveguides, optical couplers, and output optical waveguides, said chip being operable to;

receive optical signals in each of said input optical waveguides;

phase-modulate one or both received optical signals to configure a phase offset between signals received at a first optical coupler, wherein said first optical coupler generates output signals having substantially equal optical powers; and

phase-modulate one or both output signals of said first optical coupler to configure a phase offset between signals received at a second optical coupler, wherein said second optical coupler generates an output signal in a first of said output optical waveguides having an optical power of essentially zero and an output signal in a second of said output optical waveguides having a maximized optical power.