Optical resonator apparatus, optical transmitter and controlling method for optical resonator

Patent metadata

Field	Value
Publication number	US-9348154-B2
Application number	US-201414529740-A
Country	US
Kind code	B2
Filing date	Oct 31, 2014
Priority date	Nov 8, 2013
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

An optical resonator apparatus includes an optical resonator unit wherein ring optical resonators each including a first optical waveguide and a resonance wavelength adjustment electrode are coupled in cascade connection and round-trip lengths of the ring optical waveguides are different from each other and vary in order from an input side to an output side, and a controller that adjusts a resonance wavelength of each ring optical resonator in order beginning with the ring optical resonator provided at the most input side so as to match with an input light wavelength and, when an inter-channel occurs, adjusts the resonance wavelength of the first ring optical resonator from the input side so as to match with a second-matching input light wavelength and adjusts the resonance wavelengths of the second and succeeding ring optical resonators from the input side so as to match with the first-matching input light wavelength.

First claim

What is claimed is:

1. An optical resonator apparatus, comprising:
an optical resonator unit that includes a plurality of ring optical resonators each including a first optical waveguide, a second optical waveguide, a ring optical waveguide optically coupled between the first optical waveguide and the second optical waveguide, and a resonance wavelength adjustment electrode provided on the ring optical waveguide for adjusting a resonance wavelength, the plurality of ring optical resonators being coupled in cascade connection with each other, the ring optical waveguides of the plurality of ring optical resonators having round-trip lengths that are different from each other and vary in order from a light input side to a light output side; and
a controller that performs resonance wavelength adjustment control for adjusting a resonance wavelength of each of the plurality of ring optical resonators in order beginning with the ring optical resonator provided at the most light input side from among the plurality of ring optical resonators so as to match with an input light wavelength of each of a plurality of input lights having wavelengths that are different from each other and performs, when it is decided that an inter-channel occurs, re-resonance wavelength adjustment control for adjusting the resonance wavelength of the first ring optical resonator from the light input side from among the plurality of ring optical resonators so as to match with a second-matching input light wavelength and adjusting the resonance wavelengths of the second and succeeding ring optical resonators from the light input side to the first-matching input light wavelength thereby to adjust the resonance wavelength of each of the plurality of ring optical resonators so as to match with the input light wavelength of each of the plurality of input lights having wavelengths that are different from each other in order beginning with the ring optical resonator provided at the most light input side from among the plurality of ring optical resonators.

2. The optical resonator apparatus according to claim 1 , wherein the round-trip lengths of the ring optical waveguides of the plurality of ring optical resonators increase in order from the light input side toward the light output side; and
the controller adjusts, in the resonance wavelength adjustment control and the re-resonance wavelength adjustment control, the resonance wavelength of each of the plurality of ring optical resonators to a long wavelength side so as to match with the input light wavelength of each of the plurality of input lights having wavelengths that are different from each other.

3. The optical resonator apparatus according to claim 1 , wherein the resonance wavelength adjustment electrode is a heater electrode, to which current for adjusting the resonance wavelength of the ring optical resonator is supplied to heat the ring optical waveguide.

4. The optical resonator apparatus according to claim 1 , wherein the round-trip lengths of the ring optical waveguides of the plurality of ring optical resonators decrease in order from the light input side toward the light output side; and
the controller adjusts, in the resonance wavelength adjustment control and the re-resonance wavelength adjustment control, the resonance wavelength of each of the plurality of ring optical resonators to a short wavelength side so as to match with the input light wavelength of each of the plurality of input lights having wavelengths that are different from each other.

5. The optical resonator apparatus according to claim 1 , wherein the resonance wavelength adjustment electrode is a carrier injection electrode, to which current for adjusting the resonance wavelength of the ring optical resonator is supplied, to inject a carrier into the ring optical waveguide.

6. The optical resonator apparatus according to claim 1 , wherein the controller decides that the inter-channel occurs when a current amount required for the resonance wavelength adjustment control for the ring optical resonator for which the resonance wavelength adjustment control has been performed last in the resonance wavelength adjustment control is equal to or greater than a certain current amount.

7. The optical resonator apparatus according to claim 1 , wherein the controller decides that the inter-channel occurs where the order of the ring optical resonators and the order of the input light wavelengths do not match with each other when adjusting the resonance wavelengths of the ring optical resonators so as to match with the input light wavelengths in the resonance wavelength adjustment control or where a current amount required for the resonance wavelength adjustment control for the ring optical resonator for which the resonance wavelength adjustment control has been performed last in the resonance wavelength adjustment control is equal to or greater than a certain current amount.

8. The optical resonator apparatus according to claim 1 , further comprising a photodetector coupled to the first optical waveguide or the second optical waveguide of each of the plurality of ring optical resonators; wherein
the controller performs the resonance wavelength adjustment control and the re-resonance wavelength adjustment control based on information detected by the photodetector.

9. An optical transmitter, comprising:
a light source that outputs lights having wavelengths different from each other;
an optical multiplexing unit coupled with the light source;
an optical resonator unit that is coupled with the optical multiplexing unit and includes a plurality of ring optical resonators each including a first optical waveguide, a second optical waveguide, a ring optical waveguide optically coupled between the first optical waveguide and the second optical waveguide, and a resonance wavelength adjustment electrode provided on the ring optical waveguide for adjusting a resonance wavelength, the plurality of ring optical resonators being coupled in cascade connection with each other, the ring optical waveguides of the plurality of ring optical resonators having round-trip lengths that are different from each other and vary in order from a light input side to a light output side; and
a controller that performs resonance wavelength adjustment control for adjusting a resonance wavelength of each of the plurality of ring optical resonators in order beginning with the ring optical resonator provided at the most light input side from among the plurality of ring optical resonators to an input light wavelength of a corresponding one of input light components having a plurality of wavelengths different from each other and performs, when it is decided that an inter-channel occurs, re-resonance wavelength adjustment control for adjusting the resonance wavelength of the first ring optical resonator from the light input side from among the plurality of ring optical resonators so as to match with a second-matching input light wavelength and adjusting the resonance wavelengths of the second and succeeding ring optical resonators from the light input side to the first-matching input light wavelength thereby to adjust the resonance wavelengths of the plurality of ring optical resonators so as to match with the input light wavelength each of the plurality of input lights having wavelengths that are different from each other in order beginning with the ring optical resonator provided at the most light input side from among the plurality of ring optical resonators.

10. The optical transmitter according to claim 9 , wherein the round-trip lengths of the ring optical waveguides of the plurality of ring optical resonators increase in order from the light input side toward the light output side

Assignees

• Fujitsu Ltd
• Photonics Electronics Technology Res Ass

Inventors

• Hayakawa Akinori

Classifications

• H04B10/572

  Wavelength control · CPC title

• G02B6/4215

  the intermediate optical elements being wavelength selective optical elements, e.g. variable wavelength optical modules or wavelength lockers (G02B6/4246 takes precedence) · CPC title

• G02B6/28

  having data bus means, i.e. plural waveguides interconnected and providing an inherently bidirectional system by mixing and splitting signals · CPC title

• H04B10/5057

  using a feedback signal generated by analysing the optical output · CPC title

• G02F2201/16

  series; tandem · CPC title