Method And Systems For All Optical Tunable Equalizers
Methods and systems for all optical tunable equalizers may include an optical modulator comprising an input waveguide, first and second directional couplers, phase modulators, an optical delay, and an optical attenuator. The optical modulator may be operable to receive an input optical signal via the input waveguide, couple a portion of the input optical signal to a second waveguide via the first directional coupler, modulate a phase of optical signals in the input waveguide and the second waveguide using the phase modulators, and couple a feedback optical signal to the first directional coupler via the second directional coupler, the optical delay, and the optical attenuator. The optical modulator may be operable to communicate an output signal of said optical modulator from a first output of the second directional coupler. The optical modulator may be operable to communicate the feedback optical signal from a second output of the second directional coupler.
1 . A method for communication, the method comprising:
in an optical modulator comprising an input waveguide, first and second directional couplers, phase modulators, an optical delay, and an optical attenuator:
receiving an input optical signal via the input waveguide;
coupling a portion of the input optical signal to a second waveguide via the first directional coupler;
modulating a phase of optical signals in the input waveguide and the second waveguide using the phase modulators; and
coupling a feedback optical signal to the first directional coupler via the second directional coupler, the optical delay, and the optical attenuator.
2 . The method according to claim 1 , comprising communicating an output signal of said optical modulator from a first output of the second directional coupler.
3 . The method according to claim 2 , comprising communicating the feedback optical signal from a second output of the second directional coupler.
4 . The method according to claim 3 , wherein the feedback optical signal comprises an inverted, delayed, and attenuated version of the output signal.
5 . The method according to claim 1 , comprising attenuating an optical signal modulated by one of the phase modulators using a second optical attenuator.
6 . The method according to claim 1 , configuring a delay of the delay element and an attenuation of the optical attenuator.
7 . A system for communication, the system comprising:
an optical modulator comprising an input waveguide, first and second directional couplers, phase modulators, an optical delay, and an optical attenuator, the optical modulator being operable to:
receive an input optical signal via the input waveguide;
couple a portion of the input optical signal to a second waveguide via the first directional coupler;
modulate a phase of optical signals in the input waveguide and the second waveguide using the phase modulators; and
couple a feedback optical signal to the first directional coupler via the second directional coupler, the optical delay, and the optical attenuator.
8 . The system according to claim 7 , wherein the optical modulator is operable to communicate an output signal of said optical modulator from a first output of the second directional coupler.
9 . The system according to claim 8 , wherein the optical modulator is operable to communicate the feedback optical signal from a second output of the second directional coupler.
10 . The system according to claim 9 , wherein the feedback optical signal comprises an inverted, delayed, and attenuated version of the output signal.
11 . The system according to claim 7 , wherein the optical modulator is operable to attenuate an optical signal modulated by one of the phase modulators using a second optical attenuator.
12 . The system according to claim 7 , wherein a delay of the delay element and an attenuation of the optical attenuator are configurable.
13 . A method for communication, the method comprising:
in an optical modulator comprising phase modulators, first and second waveguides, first, second, and third directional couplers, and a delay element:
receiving an input optical signal via the first waveguide;
coupling a portion of the input optical signal to the second waveguide via the first directional coupler;
modulating a phase of optical signals in the input waveguide and the second waveguide using the phase modulators;
coupling a portion of optical signals between the first and second waveguides via the second directional coupler, thereby generating a data signal in the second waveguide and an inverted data signal in the first waveguide;
delaying the inverted data signal in the first waveguide using the delay element; and
coupling a portion of the delayed inverted data signal to the second waveguide using the third directional coupler.
14 . The method according to claim 13 , comprising communicating an output signal of said optical modulator from a first output of the third directional coupler.
15 . The method according to claim 13 , comprising phase shifting the data signal and the delayed inverted data signal using phase shifters in the first and second waveguides.
16 . The method according to claim 15 , wherein the phase shifters change phase of the data signal and the delayed inverted data signal at a rate slower than the phase modulators.
17 . The method according to claim 13 , wherein the delay element is configurable.
18 . The method according to claim 13 , wherein the input optical signal is a continuous wave signal.
19 . A system for communication, the system comprising:
an optical modulator comprising phase modulators, first and second waveguides, first, second, and third directional couplers, and a delay element, the optical modulator being operable to:
receive an input optical signal via the first waveguide;
couple a portion of the input optical signal to the second waveguide via the first directional coupler;
modulate a phase of optical signals in the input waveguide and the second waveguide using the phase modulators;
couple a portion of optical signals between the first and second waveguides via the second directional coupler, thereby generating a data signal in the second waveguide and an inverted data signal in the first waveguide;
delay the inverted data signal in the first waveguide using the delay element; and
couple a portion of the delayed inverted data signal to the second waveguide using the third directional coupler
20 . The system according to claim 19 , wherein the optical modulator is operable to communicate an output signal of said optical modulator from a first output of the third directional coupler.
21 . The system according to claim 19 , wherein the optical modulator is operable to phase shift the data signal and the delayed inverted data signal using phase shifters in the first and second waveguides.
22 . The system according to claim 21 , wherein the phase shifters change phase of the data signal and the delayed inverted data signal at a rate slower than that of the phase modulators.
23 . The system according to claim 19 , wherein the delay element is configurable.
24 . The system according to claim 19 , wherein the input optical signal is a continuous wave signal.