Optical modulator and method of use
An optical device. In some embodiments, the device comprises: an input waveguide, configured to receive light; a first electro-absorption modulator, coupled to receive light from the input waveguide, and operable to produce a first output or a second output, wherein the second output has a lower amplitude than the first output; a second electro-absorption modulator, coupled to receive light from the input waveguide, and operable to produce a third output or a fourth output, wherein the fourth output has a lower amplitude than the third output; and an output waveguide, coupled to receive light from the first electro-absorption modulator and the second electro-absorption modulator, and output a combined signal comprising an output of the first electro-absorption modulator and an output of the second electro-absorption modulator.
1. An optoelectronic device for modulation,
comprising:
an input waveguide;
a first intermediate waveguide and a second intermediate waveguide, each coupled to the input waveguide via an input coupler; and
an output waveguide, coupled, via an output coupler, to the first intermediate waveguide and to the second intermediate waveguide,
wherein:
the first intermediate waveguide includes a first modulating component connected in series with a first phase shifting component; and
the second intermediate waveguide includes a second modulating component connected in series with a second phase shifting component,
wherein:
the input coupler is a variable input coupler; or
the output coupler is a variable output coupler,
wherein the input coupler comprises a first Mach-Zehnder interferometer,
wherein the first Mach-Zehnder interferometer comprises a multimode interference (MMI) coupler,
wherein the optoelectronic device comprises a second Mach-Zehnder interferometer, the second Mach-Zehnder interferometer including:
as a variable input coupler of the second Mach-Zehnder interferometer, the first Mach-Zehnder interferometer;
as a first arm of the second Mach-Zehnder interferometer, the first intermediate waveguide;
as a second arm of the second Mach-Zehnder interferometer, the second intermediate waveguide; and
as a variable output coupler of the second Mach-Zehnder interferometer, a third Mach-Zehnder interferometer, and
wherein the third Mach-Zehnder interferometer comprises, as an output coupler of the third Mach-Zehnder interferometer, a 2×2 multimode interference coupler having an unequal coupling ratio.
2. The optoelectronic device of claim 1 , wherein the coupling ratio is between 0.1% and 10.0%.
3. A method, comprising:
receiving light, in the input waveguide, and
applying a modulation to the received light, with the optoelectronic device of claim 1 .
4. The method of claim 3 , wherein the coupling ratio is between 0.1% and 10.0%.
5. The method of claim 3 , further comprising:
a first heater on the first intermediate waveguide; and
a second heater on the second intermediate waveguide.
6. The method of claim 5 , wherein a heating coefficient of the first heater for the first modulating component is at least 0.01 of a heating coefficient of the first heater for the first phase shifting component.
7. The method of claim 6 , further comprising:
maintaining a relative phase in the first arm and in the second arm, at a first operating point,
maintaining a wavelength of maximum normalized extinction ratio for the first modulating component at a second operating point, and
maintaining a wavelength of maximum normalized extinction ratio for the second modulating component at a third operating point.
8. An optoelectronic device for modulation, comprising:
an input waveguide;
a first intermediate waveguide and a second intermediate waveguide, each coupled to the input waveguide via an input coupler;
an output waveguide, coupled, via an output coupler, to the first intermediate waveguide and to the second intermediate waveguide;
a first heater on the first intermediate waveguide; and
a second heater on the second intermediate waveguide,
wherein:
the first intermediate waveguide includes a first modulating component connected in series with a first phase shifting component; and
the second intermediate waveguide includes a second modulating component connected in series with a second phase shifting component,
wherein:
the input coupler is a variable input coupler; or
the output coupler is a variable output coupler,
wherein the input coupler comprises a first Mach-Zehnder interferometer,
wherein the first Mach-Zehnder interferometer comprises a multimode interference (MMI) coupler, and
wherein the optoelectronic device comprises a second Mach-Zehnder interferometer, the second Mach-Zehnder interferometer including:
as a variable input coupler of the second Mach-Zehnder interferometer, the first Mach-Zehnder interferometer;
as a first arm of the second Mach-Zehnder interferometer, the first intermediate waveguide;
as a second arm of the second Mach-Zehnder interferometer, the second intermediate waveguide; and
as a variable output coupler of the second Mach-Zehnder interferometer, a third Mach-Zehnder interferometer.
9. The optoelectronic device of claim 8 , wherein a heating coefficient of the first heater for the first modulating component is at least 0.01 of a heating coefficient of the first heater for the first phase shifting component.
10. A system, comprising an optoelectronic device for modulation and a control circuit, wherein the optoelectronic device comprises:
an input waveguide;
a first intermediate waveguide and a second intermediate waveguide, each coupled to the input waveguide via an input coupler; and
an output waveguide, coupled, via an output coupler, to the first intermediate waveguide and to the second intermediate waveguide,
wherein:
the first intermediate waveguide includes a first modulating component connected in series with a first phase shifting component; and
the second intermediate waveguide includes a second modulating component connected in series with a second phase shifting component,
wherein:
the input coupler is a variable input coupler; or
the output coupler is a variable output coupler,
wherein the input coupler comprises a first Mach-Zehnder interferometer,
wherein the first Mach-Zehnder interferometer comprises a multimode interference (MMI) coupler,
wherein the optoelectronic device comprises a second Mach-Zehnder interferometer, the second Mach-Zehnder interferometer including:
as a variable input coupler of the second Mach-Zehnder interferometer, the first Mach-Zehnder interferometer;
as a first arm of the second Mach-Zehnder interferometer, the first intermediate waveguide;
as a second arm of the second Mach-Zehnder interferometer, the second intermediate waveguide; and
as a variable output coupler of the second Mach-Zehnder interferometer, a third Mach-Zehnder interferometer, and
wherein the control circuit is configured to control a plurality of heaters, to:
maintain a relative phase in the first arm and in the second arm, at a first operating point,
maintain a wavelength of maximum normalized extinction ratio for the first modulating component at a second operating point, and
maintain a wavelength of maximum normalized extinction ratio for the second modulating component at a third operating point.