Integrated wavelength monitor

Patent metadata

Field	Value
Publication number	US-10670803-B2
Application number	US-201816183460-A
Country	US
Kind code	B2
Filing date	Nov 7, 2018
Priority date	Nov 8, 2017
Publication date	Jun 2, 2020
Grant date	Jun 2, 2020

Abstract

A silicon photonics module may include a waveguide for receiving and transmitting an optical beam. The silicon photonics module may include a tap connected to the waveguide to allow measurement of an optical power of the optical beam. The silicon photonics module may include one or more splitters connected to the waveguide to tap a portion of the optical beam from the waveguide and to split the portion of the optical beam into a first part and a second part. The silicon photonics module may include a first Mach-Zehnder interferometer (MZI) to filter the first part to allow measurement of an optical power of the filtered first part. The silicon photonics module may include a second MZI to filter the second part to allow measurement of an optical power of the filtered second part.

First claim

What is claimed is:

1. A silicon photonics module, comprising:
a waveguide for receiving and transmitting an optical beam;
a tap connected to the waveguide to allow measurement of an optical power of the optical beam;
one or more splitters connected to the waveguide to tap a portion of the optical beam from the waveguide and to split the portion of the optical beam into a first part and a second part;
a first Mach-Zehnder interferometer (MZI) to filter the first part to allow measurement of an optical power of the filtered first part; and
a second MZI to filter the second part to allow measurement of an optical power of the filtered second part,
wherein the first MZI includes a thermo-optic phase shifter and the second MZI does not include a thermo-optic phase shifter,
wherein an arm from the first MZI and an arm from the second MZI have a common length,
wherein the first MZI and the second MZI have a common free spectral range,
wherein a first peak transmission frequency of the first MZI is offset from a second peak transmission frequency of the second MZI by ¼ the common free spectral range, and
wherein the thermo-optic phase shifter is configured to provide the offset of ¼ the common free spectral range without using differing arm lengths to achieve the offset.

2. The silicon photonics module of claim 1 , wherein the first MZI and the second MZI each include a plurality of multi-mode interference couplers.

3. The silicon photonics module of claim 1 , wherein the first MZI comprises a first ring resonator and wherein the second MZI comprises a second ring resonator.

4. The silicon photonics module of claim 1 , wherein the tap is connected to a photo detector.

5. The silicon photonics module of claim 1 , wherein the thermo-optic phase shifter is on the arm from the first MZI.

6. A photonic integrated circuit, comprising:
a waveguide for receiving and transmitting an optical beam;
a tap connected to the waveguide to allow measurement of an optical power of the optical beam;
one or more splitters connected to the waveguide to split a first part and a second part from the optical beam;
a first periodic filter to filter the first part to allow measurement of an optical power of the filtered first part; and
a second periodic filter to filter the second part to allow measurement of an optical power of the filtered second part,
wherein the first periodic filter includes a thermo-optic phase shifter and the second periodic filter does not include a thermo-optic phase shifter,
wherein an arm from the first periodic filter and an arm from the second periodic filter have a common length,
wherein the first periodic filter and the second periodic filter have a common free spectral range,
wherein a first peak transmission frequency of the first periodic filter is offset from a second peak transmission frequency of the second periodic filter by ¼ the common free spectral range, and
wherein the thermo-optic phase shifter is configured to provide the offset of ¼ the common free spectral range without using differing arm lengths to achieve the offset.

7. The photonic integrated circuit of claim 6 , wherein the first periodic filter and the second periodic filter are Mach-Zehnder interferometers.

8. The photonic integrated circuit of claim 6 , wherein the one or more splitters include one or more multi-mode interference couplers or one or more directional couplers.

9. The photonic integrated circuit of claim 6 , wherein the first periodic filter and the second periodic filter are ring resonators.

10. The photonic integrated circuit of claim 6 ,
wherein the thermo-optic phase shifter is configurable to cause the first peak transmission frequency to be offset from the second peak transmission frequency.

11. The photonic integrated circuit of claim 6 , wherein the photonic integrated circuit is a silicon photonics device.

12. The photonic integrated circuit of claim 6 , wherein the tap is connected to a photo detector.

13. The photonic integrated circuit of claim 6 , wherein the thermo-optic phase shifter is on the arm from the first periodic filter.

14. An integrated wavelength locker, comprising:
a substrate comprising:
a splitter to split a first part and a second part from an optical beam;
a first wavelength filter to filter the first part to allow measurement of a first optical power of the filtered first part; and
a second wavelength filter to filter the second part to allow measurement of a second optical power of the filtered second part,
wherein the first wavelength filter includes a thermo-optic phase shifter and the second wavelength filter does not include a thermo-optic phase shifter,
wherein an arm from the first wavelength filter and an arm from the second wavelength filter have a common length,
wherein the first wavelength filter and the second wavelength filter have a common free spectral range,
wherein a first peak transmission frequency of the first wavelength filter is offset by ¼ the common free spectral range from a second peak transmission frequency of the second wavelength filter, and
wherein the thermo-optic phase shifter is configured to provide the offset of ¼ the common free spectral range without using differing arm lengths to achieve the offset.

15. The integrated wavelength locker of claim 14 , wherein the substrate is implemented in at least one of:
a silicon photonics module,
a photonic integrated circuit,
a planar lightwave chip, or
an indium-phosphide module.

16. The integrated wavelength locker of claim 14 , further comprising:
a first photo detector to allow the measurement of the first optical power;
a second photo detector to allow the measurement of the second optical power; and
a third photo detector to allow measurement of a third optical power of the optical beam.

17. The integrated wavelength locker of claim 16 , wherein the first wavelength filter is a first ring resonator and the second wavelength filter is a second ring resonator; and
wherein the first photo detector is connected to a first through port of the first ring resonator and the second photo detector is connected to a second through port of the second ring resonator.

18. The integrated wavelength locker of claim 16 , wherein the first wavelength filter is a first ring resonator and the second wavelength filter is a second ring resonator; and
wherein the first photo detector is connected to a first drop port of the first ring resonator and the second photo detector is connected to a second drop port of the second ring resonator.

19. The integrated wavelength locker of claim 14 , wherein the substrate further comprises:
a waveguide to receive and to transmit the optical beam.

20. The integrated wavelength locker of claim 14 , further comprising a tap connected to a waveguide that transmits the optical beam, and
wherein the tap is connected to a photo detector.

Assignees

• Lumentum Operations Llc

Inventors

• Daniel Brian

Classifications

• G02B6/29338

  Loop resonators · CPC title

• G01M11/00

  Testing of optical apparatus; Testing structures by optical methods not otherwise provided for · CPC title

• G02B6/29341

  Loop resonators operating in a whispering gallery mode evanescently coupled to a light guide, e.g. sphere or disk or cylinder (evanescent coupling for sensing fluorescence G01N21/648) · CPC title

• G02B6/29353

  with a wavelength selective element in at least one light guide interferometer arm, e.g. grating, interference filter, resonator · CPC title

• G02B6/12007 Primary

  forming wavelength selective elements, e.g. multiplexer, demultiplexer · CPC title