WDM channel reassignment

Patent metadata

Field	Value
Publication number	US-12009912-B2
Application number	US-202217888947-A
Country	US
Kind code	B2
Filing date	Aug 16, 2022
Priority date	Mar 23, 2022
Publication date	Jun 11, 2024
Grant date	Jun 11, 2024

Abstract

An optical device includes a first waveguide, ring-shaped waveguides adjacent to the first waveguide, and heaters coupled to the ring-shaped waveguides in one-to-one correspondence. A method includes coupling a first light source with a first wavelength to the first waveguide, increasing electric current through the heaters until a first one of the ring-shaped waveguides resonates, assigning the first one of the ring-shaped waveguides to the first wavelength, resetting the electric current through the heaters to the initial electric current, coupling a second light source with a second wavelength to the first waveguide wherein the second wavelength is different from the first wavelength, increasing the electric current through the heaters until a second one of the ring-shaped waveguides resonates wherein the second one of the ring-shaped waveguides is different from the first one of the ring-shaped waveguides, and assigning the second one of the ring-shaped waveguides to the second wavelength.

First claim

What is claimed is:

1. A method for operating an optical device, wherein the optical device includes a first waveguide, multiple ring-shaped waveguides adjacent to the first waveguide, and multiple heaters coupled to the ring-shaped waveguides in one-to-one correspondence, wherein each of the multiple heaters is supplied with an initial electric current, the method comprising:
coupling a first light source with a first wavelength to the first waveguide;
increasing electric current through the heaters until a first one of the ring-shaped waveguides resonates, wherein the first one of the ring-shaped waveguides is coupled to a first one of the heaters;
assigning the first one of the ring-shaped waveguides to the first wavelength;
resetting the electric current through the heaters or the heaters excluding the first one of the heaters to the initial electric current;
coupling a second light source with a second wavelength to the first waveguide, wherein the second wavelength is different from the first wavelength;
increasing the electric current through the heaters or the heaters excluding the first one of the heaters until a second one of the ring-shaped waveguides resonates, wherein the second one of the ring-shaped waveguides is different from the first one of the ring-shaped waveguides; and
assigning the second one of the ring-shaped waveguides to the second wavelength.

2. The method of claim 1 , wherein the initial electric current is substantially zero amperes.

3. The method of claim 1 , wherein the optical device includes multiple heater control loops that are configured to control the multiple heaters in one-to-one correspondence, further comprising:
before the coupling of the first light source, disabling the heater control loops; and
after the assigning of the first one of the ring-shaped waveguides to the first wavelength, enabling one of the heater control loops that corresponds to the first one of the heaters.

4. The method of claim 1 , wherein the multiple ring-shaped waveguides include four or more ring-shaped waveguides.

5. The method of claim 1 , wherein the optical device includes an optical transmitter and each of the ring-shaped waveguides is a part of a micro-ring modulator.

6. The method of claim 5 , after the assigning of the second one of the ring-shaped waveguides to the second wavelength, further comprising:
modulating the first wavelength by applying a first electric signal to the first one of the ring-shaped waveguides, thereby generating a modulated first light signal;
modulating the second wavelength by applying a second electric signal to the second one of the ring-shaped waveguides, thereby generating a modulated second light signal; and
multiplexing the modulated first light signal and the modulated second light signal into a transmitting light signal.

7. The method of claim 1 , wherein the optical device includes an optical receiver and each of the ring-shaped waveguides is a part of a ring resonator.

8. The method of claim 7 , after the assigning of the second one of the ring-shaped waveguides to the second wavelength, further comprising:
receiving a light signal having a first component at the first wavelength and a second component at the second wavelength;
coupling the light signal to the multiple ring-shaped waveguides; and
demultiplexing the light signal to a first light signal through the first one of the ring-shaped waveguides and a second light signal through the second one of the ring-shaped waveguides.

9. A method for operating an optical transmitter, wherein the optical transmitter includes a first waveguide, multiple micro-ring modulators (MRMs) adjacent to the first waveguide, and multiple heaters coupled to the MRMs in one-to-one correspondence, wherein each of the multiple heaters is supplied with an initial electric current, the method comprising the steps of:
coupling a light source with a wavelength to the first waveguide;
increasing electric current through each of the heaters until one of the MRMs resonates, wherein the one of the MRMs is coupled to one of the heaters;
assigning the one of the MRMs to the wavelength;
resetting the electric current through the heaters or the heaters excluding the one of the heaters to the initial electric current; and
repeating the steps of coupling, increasing, assigning, and resetting until each of the MRMs is assigned to a different wavelength.

10. The method of claim 9 , before the step of coupling, further comprising:
turning off an automatic heater control loop to each of the multiple heaters.

11. The method of claim 9 , wherein the MRMs include a multiple of four MRMs.

12. The method of claim 9 , further comprising:
biasing each of the MRMs to a fixed biasing voltage during the steps of coupling, increasing, assigning, resetting, and repeating.

13. The method of claim 9 , further comprising:
applying a toggling electric signal to each of the MRMs during the steps of coupling, increasing, assigning, resetting, and repeating.

14. The method of claim 9 , further comprising:
storing values of electric current through each of the heaters that cause the respective MRMs to resonate during the step of increasing electric current.

15. The method of claim 9 , wherein the steps of coupling, increasing, assigning, resetting, and repeating are performed during an initialization procedure of the optical transmitter.

16. A system comprising:
an optical transmitter, wherein the optical transmitter includes a first waveguide, multiple micro-ring modulators (MRMs) disposed adjacent to the first waveguide, and multiple heaters coupled to the MRMs in one-to-one correspondence;
multiple heater controllers coupled to the multiple heaters in one-to-one correspondence; and
an assignment controller that is configured to perform:
coupling a light source to the first waveguide;
instructing the heater controllers to increase electric current through the heaters until one of the MRMs resonates, wherein the one of the MRMs is coupled to one of the heaters; and
assigning the one of the MRMs to a wavelength of the light source.

17. The system of claim 16 , wherein the assignment controller is further configured to perform:
resetting the electric current through the heaters or the heaters excluding the one of the heaters to an initial electric current; and
repeating the steps of coupling, instructing, and resetting until each of the MRMs is assigned to a different wavelength.

18. The system of claim 17 , wherein the assignment controller is further configured to perform:
storing results of assigning the MRMs to the different wavelengths.

19. The system of claim 16 , wherein the optical transmitter further includes multiple ring modulator drivers (RMDs) that are coupled to the MRMs in one-to-one correspondence.

20. The system of claim 16 , wherein the optical transmitter further includes multiple photo detectors, and each of the photo detectors is coupled between one of the MRMs and a corresponding one of the heater controllers.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Lin Chih-Chang
• Chern Chan-Hong
• Rusu Stefan
• Song Weiwei
• Cho Lan-Chou

Classifications

• H04J14/02

  Wavelength-division multiplex systems · CPC title

• H04B10/806

  Arrangements for feeding power · CPC title

• H04B10/801

  using optical interconnects, e.g. light coupled isolators, circuit board interconnections · CPC title

• H04B10/516

  Details of coding or modulation · CPC title

• H04B10/506 Primary

  Multiwavelength transmitters · CPC title