Reduced crosstalk photonic switch

Patent metadata

Field	Value
Publication number	US-10244297-B1
Application number	US-201815920769-A
Country	US
Kind code	B1
Filing date	Mar 14, 2018
Priority date	Mar 14, 2018
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

Described are various configurations of reduced crosstalk optical switches. Various embodiments can reduce or entirely eliminate crosstalk using a coupler that has a power-splitting ratio that compensates for amplitude imbalance caused by phase modulator attenuation. Some embodiments implement a plurality of phase modulators and couplers as part of a dilated switch network to increase overall bandwidth and further reduce potential for crosstalk.

First claim

What is claimed is:

1. A method of routing light in a switch network, the method comprising:
receiving, by multiple phase modulators, multiple beam components of a light beam;
generating, using one of the multiple phase modulators, a phase-shifted beam component by phase-shifting one of the multiple beam components of the light beam such that the phase-shifted beam component is out of phase with at least one other beam component from the multiple beam components of the light beam, the phase-shifted beam component exhibiting attenuation caused by the one of the multiple phase modulators; and
combining, using an optical coupler, the phase-shifted beam component with the at least one other beam component such that constructive interference occurs for a first output port of the optical coupler and destructive interference occurs for a second output port of the optical coupler, the optical coupler having a physical shape that compensates for the attenuation caused by the one of the multiple phase modulators.

2. The method of claim 1 , wherein the multiple phase modulators are silicon-based modulators that phase-shift the one of the multiple beam components based on a quantity of embedded positive and negative carriers.

3. The method of claim 1 , wherein the multiple phase modulators include a first phase modulator and a second phase modulator, wherein the phase-shifted beam component is phase-shifted by the first phase modulator, and wherein the second phase modulator is in an off-state that passes the at least one other beam component un-shifted.

4. The method of claim 3 , wherein generating the phase-shifted beam component comprises shifting, using the first phase modulator, the phase of the one of the multiple beam components by approximately 90 degrees.

5. The method of claim 3 , wherein generating the phase-shifted beam component comprises shifting, using the first phase modulator, the phase of the one of the multiple beam components by approximately 180 degrees.

6. The method of claim 1 , wherein the optical coupler has a power splitting ratio that compensates for attenuation in the modulated beam component.

7. The method of claim 6 , wherein the power splitting ratio is one of: t^2/(1+t^2), where t is a ratio of field transmission coefficients of the multiple phase modulators.

8. The method of claim 6 , wherein the power splitting ratio is t/(1+t), where t is a ratio of field transmission coefficients of the multiple phase modulators.

9. The method of claim 1 , wherein the optical coupler has tapered sides that modify a superposition of light in the optical coupler such that a power splitting ratio of the optical coupler compensates for attenuation in the modulated beam component.

10. The method of claim 1 , wherein the light beam includes an individual data stream, and the multiple beam components of the optical signal include facsimiles of the data stream.

11. The method of claim 1 , further comprising:
receiving, using an additional optical coupler, the light beam;
generating, using the additional optical coupler, the multiple beam components by splitting the light beam such that the multiple beam components have equal power; and
outputting, using the additional optical coupler, the multiple beam components to the multiple phase modulators.

12. An optical device for routing signals in a switch network, the optical device comprising:
a plurality of phase modulators receiving multiple beam components, one of the plurality of phase modulators generating a phase-shifted beam component by phase-shifting one of the multiple beam components such that the phase-shifted beam component is out of phase with at least one other beam component in the multiple beam components, the phase-shifted beam component exhibiting attenuation caused by the one of the plurality of phase modulators; and
an optical coupler to combine the phase-shifted beam component with the at least one other beam component such that constructive interference occurs for a first output port of the optical coupler and destructive interference occurs for a second output port of the optical coupler, the optical coupler having a physical shape that compensates for the attenuation caused by the one of the plurality of phase modulators.

13. The optical device of claim 12 , wherein the plurality of phase modulators are silicon-based modulators that modulate based on a quantity of embedded positive and negative carriers.

14. The optical device of claim 12 , wherein the plurality of phase modulators include a first phase modulator and a second phase modulator, wherein the phase-shifted beam component is phase-shifted by the first phase modulator, and wherein the second phase modulator is an off-state that passes the at least one other beam component un-shifted.

15. The optical device of claim 12 , wherein the optical coupler has a power splitting ratio that compensates for attenuation in the modulated beam component, wherein the power splitting ratio is t^2/(1+t^2), where t is field transmission.

16. The optical device of claim 12 , wherein the optical coupler has tapered sides that modify a superposition of light in the optical coupler such that a power splitting ratio of the optical coupler compensates for attenuation in the phase-shifted beam component.

Assignees

• Juniper Networks Inc

Inventors

• Roth Jonathan Edgar

Classifications

• G02F1/3136

  of interferometric switch type · CPC title

• G02B6/355

  1x2 switch, i.e. one input and a selectable single output of two possible outputs · CPC title

• H04Q2011/0015

  using splitting combining · CPC title

• H04Q11/0005 Primary

  Switch and router aspects · CPC title

• H04Q2011/0049

  Crosstalk reduction; Noise; Power budget · CPC title