Method and system for a polarization immune wavelength division multiplexing demultiplexer

• US 9,577,780 B2
• Filed: 06/26/2015
• Issued: 02/21/2017
• Est. Priority Date: 06/26/2014
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Luxtera Incorporated (Cisco Systems, Inc.)
• Inventors: Welch, Brian
• Primary Examiner(s): VANDERPUYE, KENNETH N
• Assistant Examiner(s): Sandhu, Amritbir
• Application Number:
  US14/752,709
• Publication Number:
  US 20160036550A1
• Time in Patent Office: 606 Days
• US Class Current: 1/1
• CPC Class Codes: G02B 6/12007 forming wavelength selective elements, e.g. multiplexer, demultiplexer
• CPC Class Codes: G02B 6/1225 comprising photonic band-gap structures or photonic lattices
• CPC Class Codes: G02B 6/2773 Polarisation splitting or combining
• CPC Class Codes: G02B 6/2786 Reducing the polarisation degree, i.e. depolarisers, scramblers, unpolarised output
• CPC Class Codes: G02B 6/29352 in a light guide
• CPC Class Codes: G02B 6/29353 with a wavelength selective element in at least one light guide interferometer arm, e.g. grating, interference filter, resonator
• CPC Class Codes: G02B 6/2938 for multiplexing or demultiplexing, i.e. combining or separating wavelengths, e.g. 1xN, NxM
• CPC Class Codes: G02B 6/29395 configurable, e.g. tunable or reconfigurable switching G02B6/35
• CPC Class Codes: G02B 6/29397 Polarisation insensitivity
• CPC Class Codes: G02B 6/34 utilising prism or grating G02B6/293 takes precedence
• CPC Class Codes: G02B 6/4215 the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers G02B6/4246 takes precedence
• CPC Class Codes: G02F 1/025 in an optical waveguide structure G02F1/017, G02F1/2257 take precedence
• CPC Class Codes: G02F 1/212 Mach-Zehnder type
• CPC Class Codes: G02F 1/225 in an optical waveguide structure
• CPC Class Codes: G02F 1/2257 the optical waveguides being made of semiconducting material
• CPC Class Codes: G02F 2203/06 Polarisation independent
• CPC Class Codes: H04B 10/40 Transceivers
• CPC Class Codes: H04B 10/5161 Combination of different modulation schemes
• CPC Class Codes: H04B 10/801 using optical interconnects, e.g. light coupled isolators, circuit board interconnections
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0221 : Power control, e.g. to keep the total optical power constant
• CPC Class Codes: H04J 14/0307 : Multiplexers; Demultiplexers

Abstract

Methods and systems for a polarization immune wavelength division multiplexing demultiplexer are disclosed and may include, in an optoelectronic transceiver having an input coupler, a demultiplexer, and an amplitude scrambler: receiving input optical signals of different polarization via the input coupler, communicating the input optical signals to the amplitude scrambler via waveguides, configuring the average optical power in each of the waveguides utilizing the amplitude scrambler, and demultiplexing the optical signals utilizing the demultiplexer. The amplitude scrambler may include phase modulators and a coupling section. The phase modulators may include sections of P-N junctions in the two waveguides. The demultiplexer may include a Mach-Zehnder Interferometer. The demultiplexed signals may be received utilizing photodetectors. The input coupler may include a polarization splitting grating coupler. The average optical power may be configured above which demultiplexer control circuitry is able to control the demultiplexer to process incoming optical signals.

Claims

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

in a transceiver having an input coupler, a demultiplexer, and an amplitude scrambler;

receiving at least two modulated input optical signals of different polarization via the input coupler;

communicating the at least two input optical signals to the amplitude scrambler via two waveguides;

configuring the average optical power in each of the two waveguides utilizing the amplitude scrambler; and

demultiplexing the at least two optical signals utilizing the demultiplexer, wherein the demultiplexer comprises a plurality of phase modulation sections coupled to outputs of the amplitude scrambler.

2. The method according to claim 1, wherein the amplitude scrambler comprises phase modulators and a coupling section.

3. The method according to claim 1, wherein the phase modulators comprise sections of P-N junctions in the two waveguides.

4. The method according to claim 1, wherein the demultiplexer comprises a Mach-Zehnder Interferometer.

5. The method according to claim 1, comprising receiving the demultiplexed signals utilizing at least two photodetectors.

6. The method according to claim 1, wherein the input coupler comprises a polarization splitting grating coupler.

7. The method according to claim 1, wherein the average optical power is configured above a threshold value that is an optical power level above which demultiplexer control circuitry is able to control the demultiplexer to process incoming optical signals.

8. The method according to claim 1, wherein the transceiver comprises an optoelectronic transceiver in a silicon photonically-enabled integrated circuit.

9. The method according to claim 8, wherein the silicon photonically-enabled integrated circuit is in a single complementary-metal oxide semiconductor (CMOS) die.

10. The method according to claim 8, wherein the silicon photonically-enabled integrated circuit is in two CMOS die, a first die comprising electronic devices and a second die comprising optical devices.

11. A system for communication, the system comprising:

a transceiver comprising an input coupler, a demultiplexer, and an amplitude scrambler, the transceiver being operable to;

receive at least two modulated input optical signals of different polarization via the input coupler;

communicate the at least two input optical signals to the amplitude scrambler via two waveguides;

configure the average optical power in each of the two waveguides utilizing the amplitude scrambler; and

demultiplex the at least two optical signals utilizing the demultiplexer wherein the demultiplexer comprises a plurality of phase modulation sections coupled to outputs of the amplitude scrambler.

12. The system according to claim 11, wherein the amplitude scrambler comprises phase modulators and a coupling section.

13. The system according to claim 11, wherein the phase modulators comprise sections of P-N junctions in the two waveguides.

14. The system according to claim 11, wherein the demultiplexer comprises a Mach-Zehnder Interferometer.

15. The system according to claim 11, wherein the transceiver is operable to receive the demultiplexed signals utilizing at least two photodetectors.

16. The system according to claim 11, wherein the input coupler comprises a polarization splitting grating coupler.

17. The system according to claim 11, wherein the average optical power is configured above a threshold value, and wherein the threshold value is an optical power level above which demultiplexer control circuitry is able to control the demultiplexer to process incoming optical signals.

18. The system according to claim 11, wherein the transceiver comprises an optoelectronic transceiver in a silicon photonically-enabled integrated circuit in a single complementary-metal oxide semiconductor (CMOS) die.

19. The system according to claim 11, wherein the transceiver comprises an optoelectronic transceiver in a silicon photonically-enabled integrated circuit in two CMOS die, a first die comprising electronic devices and a second die comprising optical devices.

20. A system for communication, the system comprising:

a transceiver comprising a polarization splitting grating coupler (PSGC), a demultiplexer, and an amplitude scrambler, the transceiver being operable to;

receive at least two modulated input optical signals of different polarization via the PSGC;

communicate the at least two input optical signals to the amplitude scrambler via two waveguides;

configure the average optical power in each of the two waveguides utilizing the amplitude scrambler; and

demultiplex the at least two optical signals utilizing the demultiplexer wherein the demultiplexer comprises a plurality of phase modulation sections coupled to outputs of the amplitude scrambler.