Optical modulator and method of use

Patent metadata

Field	Value
Publication number	US-12001115-B2
Application number	US-202217712036-A
Country	US
Kind code	B2
Filing date	Apr 1, 2022
Priority date	Mar 17, 2017
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

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.

First claim

What is claimed is:

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.

Assignees

• Rockley Photonics Ltd
• California Inst Of Techn
• Rockley Phonics Ltd

Inventors

• Hashemi Talkhooncheh Arian
• Emami Azita
• Zhang Yi
• Zilkie Aaron

Classifications

• G02F1/212 Primary

  Mach-Zehnder type · CPC title

• G02F1/225

  in an optical waveguide structure · CPC title

• H04B10/541

  Digital intensity or amplitude modulation · CPC title

• G02F1/0121 Primary

  Operation of devices; Circuit arrangements, not otherwise provided for in this subclass · CPC title

• H04B10/524

  Pulse modulation · CPC title