ELECTRO-OPTIC PHASE MODULATOR WITH NO RESIDUAL AMPLITUDE MODULATION
First Claim
1. An optical phase modulator, comprising:
- an input port, configured to receive a light source;
an output port configured to provide a phase modulated output signal based on the received light source;
a first optical coupler coupled to the input port and configured to split the light source into a first optical path of a Mach Zehnder Interferometer (MZI) and a second optical path of the MZI;
a static phase shifter in the first optical path;
a phase modulator in the second optical path; and
a second optical coupler coupled to the output port and configured to combine the first optical path and the second optical path,wherein the first and second optical couplers are adjusted such that the phase modulated optical signal at the output port provides a substantially constant amplitude that is independent of an insertion loss variation introduced by the phase modulator.
1 Assignment
0 Petitions
Accused Products
Abstract
An optical phase modulator includes an input source that is configured to receive a light source. There is an output operative to provide a phase modulated output signal based on the received light source. There is a first optical coupler configured to split the light source into a first optical path of a Mach Zehnder Interferometer (MZI) and a second optical path of the MZI. A static phase shifter is configured to provide a static phase shift to the first optical path. There is a phase modulator in the second optical path. There is a second optical coupler configured to combine the first optical path and the second optical path. The first and second optical couplers are tuned such that the phase modulated optical signal at the output provides a substantially constant amplitude that is independent of a change in loss introduced by the phase modulator.
18 Citations
24 Claims
-
1. An optical phase modulator, comprising:
-
an input port, configured to receive a light source; an output port configured to provide a phase modulated output signal based on the received light source; a first optical coupler coupled to the input port and configured to split the light source into a first optical path of a Mach Zehnder Interferometer (MZI) and a second optical path of the MZI; a static phase shifter in the first optical path; a phase modulator in the second optical path; and a second optical coupler coupled to the output port and configured to combine the first optical path and the second optical path, wherein the first and second optical couplers are adjusted such that the phase modulated optical signal at the output port provides a substantially constant amplitude that is independent of an insertion loss variation introduced by the phase modulator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 24)
-
-
9. A system for phase modulation, comprising:
-
an input port, configured to receive a light source; an output port configured to provide a phase modulated output signal based on the received light source; a first optical coupler coupled to the input port and configured to split the light source into a first optical path of a Mach Zehnder Interferometer (MZI) and a second optical path of the MZI; a static phase shifter in the first optical path; a phase modulator in the second optical path; and a second optical coupler coupled to the output port and configured to combine the first optical path and the second optical path, wherein the first and second optical couplers are adjusted such that the phase modulated optical signal at the output port provides a substantially constant amplitude that is independent of an insertion loss variation introduced by the phase modulator. - View Dependent Claims (10, 11, 12, 13, 14, 15)
-
-
16. An optical switch, comprising:
-
an input comprising a first input port and a second input port; an output comprising a first output port and a second output port; a first optical coupler configured to combine a signal from the first input port and a signal from the second input port; a second optical coupler coupled to a first output of the first optical coupler and configured to split a signal of the first output of the first optical coupler into a first optical path of an upper Mach Zehnder Interferometer (MZI) and a second optical path of the upper MZI; a first static phase shifter configured to provide a static phase shift to the second optical path of the upper MZI; a first phase modulator in the first optical path of the upper MZI; a third optical coupler configured to combine the first optical path and the second optical path of the upper MZI, a fourth optical coupler coupled to a second output of the first optical coupler and configured to split a signal of the second output of the first optical coupler into a first optical path of a lower MZI and a second optical path of the lower MZI; a second static phase shifter configured to provide a static phase shift to the first optical path of the lower MZI; a second phase modulator in the second optical path of the lower MZI; a fifth optical coupler configured to combine the first optical path and the second optical path of the lower MZI; and a sixth optical coupler configured to combine an output of the third optical coupler and an output of the fifth optical coupler, wherein the second, third, fourth, and fifth optical couplers are adjusted such that a phase modulated optical signal at an output of the optical phase modulator provides a substantially constant amplitude that is independent of an insertion loss variation introduced by the first and an insertion loss variation of the second phase modulator. - View Dependent Claims (17, 18)
-
-
19. An optical switch, comprising:
-
an input comprising a first input port and a second input port; an output comprising a first output port and a second output port; a first optical coupler configured to combine a signal from the first input port and the second input port; a second optical coupler coupled to a first output of the first optical coupler and configured to split a signal of the first output of the first optical coupler into a first optical path of an upper Mach Zehnder Interferometer (MZI) and a second optical path of the upper MZI; a first phase modulator in the first optical path of the upper MZI; a first phase shifter configured to provide a static phase shift to the second optical path of the upper MZI; a third optical coupler configured to combine the first optical path and the second optical path of the upper MZI; a loss compensator coupled to a second output of the first optical coupler and configured to match an amplitude loss incurred on the upper MZI; and a fourth optical coupler configured to combine an output of the third optical coupler and an output of the loss compensator, wherein the second and third optical couplers are adjusted such that a phase modulated optical signal at an output of the optical phase modulator provides a substantially constant amplitude that is independent of an insertion loss variation introduced by the first phase modulator. - View Dependent Claims (20)
-
-
21. A method of modulating an optical switch, comprising:
-
providing a Mach Zehnder Interferometer (MZI) having a first optical path, a second optical path, a phase modulator in the second optical path, a first optical coupler at an input of the MZI, and a second optical coupler at an output of the MZI; splitting, by the first optical coupler, an input signal into the first optical path and the second optical path; changing the effective path length in the first optical path such that it provides a static phase shift to the first optical path; modulating the phase in the second optical path via a phase modulator; combining, by the second optical coupler, an output of the first optical path and an output of the second optical path; and tuning a coupling coefficient of the first optical coupler and a coupling coefficient of the second optical coupler such that an output of the second optical coupler provides a substantially constant amplitude that is independent of a change in loss introduced by the phase modulator. - View Dependent Claims (22, 23)
-
Specification