Reduced crosstalk photonic switch
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.
1. A method for routing light using an optical switch, the method comprising:
receiving light at the optical switch, the optical switch having a physical shape that compensates for attenuation differences of internal light in the optical switch;
generating modulated light using an optical modulator in the optical switch, the modulated light exhibiting attenuation caused by the optical modulator; and
coupling the modulated light using the optical switch such that constructive interference occurs for a first output port of the optical switch and destructive interference occurs for a second output port of the optical switch due to the physical shape of the optical switch.
2. The method of claim 1 , wherein the optical switch comprises a coupler that exhibits the physical shape that compensates for the attenuation differences of the light in the coupler.
3. The method of claim 2 , wherein the coupler has tapered sides that modify a superposition of the light in the coupler.
4. The method of claim 3 , wherein the superposition of the light in the coupler is modified by the tapered sides such that a power splitting ratio of the coupler compensates for attenuation differences in the light in the coupler.
5. The method of claim 4 , wherein the power splitting ratio is t{circumflex over ( )}2/(1+t{circumflex over ( )}2), where t is a ratio of field transmission coefficients of the optical modulator.
6. The method of claim 4 , wherein the power splitting ratio is t/(1+t), where t is a ratio of field transmission coefficients of the optical modulator.
7. The method of claim 1 , wherein the optical modulator is a phase modulator that generates the modulated light using phase modulation.
8. The method of claim 7 , wherein generating the modulated light comprises shifting, using the phase modulator, a phase of a portion of the light in the optical switch by approximately 90 degrees.
9. The method of claim 7 , wherein generating the modulated light comprises shifting, using the phase modulator, a phase of a portion of the light in the optical switch by approximately 180 degrees.
10. The method of claim 1 , wherein the optical modulator generates the modulated light based on a quantity of embedded positive and negative carriers in the optical modulator.
11. The method of claim 1 , wherein the optical modulator is a first optical modulator and the optical switch comprises a second optical modulator, wherein the first optical modulator generates the modulated light while the second optical modulator is inactive.
12. The method of claim 11 , wherein the second optical modulator that is inactive passes light unmodulated.
13. An optical switch for routing light, the optical switch comprising:
an input port to receive the light;
a first output port;
a second output port; and
an optical modulator configured to generate modulated light, the modulated light exhibiting attenuation caused by the optical modulator, the optical switch having a physical shape that compensates for attenuation differences by causing constructive interference occurs for a first output port of the optical switch and destructive interference occurs for a second output port of the optical switch due to the physical shape of the optical switch.
14. The optical switch of claim 13 , wherein the optical switch comprises a coupler that exhibits the physical shape that compensates for the attenuation differences of the light in the coupler.
15. The optical switch of claim 14 , wherein the coupler has tapered sides that modify a superposition of the light in the coupler.
16. The optical switch of claim 15 , wherein the superposition of the light in the coupler is modified by the tapered sides such that a power splitting ratio of the coupler compensates for attenuation differences in the light in the coupler.
17. The optical switch of claim 13 , wherein the optical modulator is a phase modulator that generates the modulated light using phase modulation.
18. The optical switch of claim 13 , wherein the optical modulator generates the modulated light based on a quantity of embedded positive and negative carriers in the optical modulator.
19. The optical switch of claim 13 , wherein the optical modulator is a first optical modulator, and wherein the optical switch further comprises a second optical modulator, wherein the first optical modulator generates the modulated light while the second optical modulator is inactive.
20. The optical switch of claim 19 , wherein the second optical modulator that is inactive passes light unmodulated.