Method and device for chromatic dispersion compensation

Patent metadata

Field	Value
Publication number	US-2019349092-A1
Application number	US-201916410879-A
Country	US
Kind code	A1
Filing date	May 13, 2019
Priority date	May 11, 2018
Publication date	Nov 14, 2019
Grant date	—

Abstract

A tunable optical dispersion compensator (TODC) for providing chromatic dispersion (CD) compensation of optical signals in a plurality of optical channels comprises: a plurality of CD compensation fibers; a tunable optical switch configurable for directing an optical signal in any of the plurality of optical channels to one of the plurality of fibers, dependent on a central wavelength of the optical signal; a first switch configurable for directing all signals in the plurality of optical channels to a first CD compensation fiber, in a first mode of operation, and for bypassing the first CD compensation fiber in a second mode of operation; and, the first CD compensation fiber, wherein the first switch and the tunable optical switch are connected so as to enable combining CD compensation provided by the first CD compensation fiber and CD compensation provided by any one of the plurality of CD compensation fibers.

First claim

1 . A tunable optical dispersion compensator (TODC) for at least partial chromatic dispersion (CD) compensation of optical signals in a plurality of optical channels, comprising:
a plurality of CD compensation fibers having dispersion values associated with the plurality of CD compensation fibers, wherein the least of the dispersion values is less than a predefined resolution and each of other dispersion values is greater than its preceding dispersion value by no more than the predefined resolution, when the dispersion values are arranged in increasing order; a tunable optical switch configurable for directing an optical signal in any of the plurality of optical channels to one of the plurality of fibers, dependent on a central wavelength of the optical signal; a first switch configurable for directing all signals in the plurality of optical channels to a first CD compensation fiber, in a first mode of operation, and for bypassing the first CD compensation fiber in a second mode of operation; and, the first CD compensation fiber, wherein the first switch and the tunable optical switch are connected so as to enable combining CD compensation provided by the first CD compensation fiber and CD compensation provided by any one of the plurality of CD compensation fibers.

2 . The TODC as defined in claim 1 , wherein the first switch is a 2×2 switch.

3 . The TODC as defined in claim 2 , further comprising a second CD compensation fiber and a second 2×2 switch for providing signals in the plurality of optical channels to the second CD compensation fiber or bypassing the second CD compensation fiber.

4 . The TODC as defined in claim 2 , wherein the tunable optical switch is a 1×M switch.

5 . The TODC as defined in claim 4 , comprising a M×1 combiner for combining the signals propagating in the plurality of DC compensation fibers into a broadband signal.

6 . The TODC as defined in claim 4 , comprising a mirror for reflecting the signals propagating in the plurality of DC compensation fibers back into respective fibers.

7 . The TODC as defined in claim 1 , wherein the first switch is a 1×M1 switch, M1=2 . . . 8.

8 . The TODC as defined in claim 7 , comprising a mirror for reflecting a signals propagating in the first DC compensation fiber back into first DC compensation fiber.

9 . The TODC as defined in claim 2 , wherein each of the dispersion values associated with the plurality of DC compensation fibers, other than the least value, is greater than its preceding dispersion value by the predefined resolution.

10 . The TODC as defined in claim 9 , wherein the least of the dispersion values associated with the plurality of DC compensation fibers is equal to a half of the predefined resolution.

11 . The TODC as defined in claim 9 , wherein the predefined resolution is 50 ps.

12 . The TODC as defined in claim 4 , wherein the plurality of fibers comprises N≥7 fibers, and M is equal to N, N+1, or N+2.

13 . The TODC as defined in claim 10 , wherein N=M=8, the dispersion values associated with the first and second CD compensation fibers are 400 and 800 ps, and the predefined resolution is 50 ps.

14 . The TODC as defined in claim 1 , wherein the first CD compensation fiber has a length such that the greatest of dispersion values associated with the plurality of CD compensation fibers is less than the least of dispersion values formed by adding a dispersion value associated with the first CD compensation fiber to the dispersion values associated with the plurality of CD compensation fibers by no more than the predefined resolution.

15 . A method of chromatic dispersion (CD) compensation in an optical system comprising span fiber for propagating optical signals in a plurality of optical channels, and a plurality of tails, each for propagating an optical signal in one of the plurality of optical channels, the method comprising:
determining one or more parameters related to chromatic dispersion in the span fiber, determining a remote tail length for each of the plurality of optical channels, and compensating the chromatic dispersion of the span fiber and tail chromatic dispersion on per-channel basis using a tunable compensator, wherein the one or more parameters related to chromatic dispersion in the span fiber and the remote tail length for signals in each of the plurality of optical channels are used for configuring the tunable compensator.

16 . The method as defined in claim 15 , wherein determining the one or more parameters related to the chromatic dispersion in the span fiber comprises using a BER monitor.

17 . The method as defined in claim 16 , wherein determining the one or more parameters related to the chromatic dispersion in the span fiber comprises close loop dispersion compensation control comprising using the BER monitor.

18 . The method as defined in claim 17 , wherein determining the remote tail lengths comprises using an optical time-domain reflectometer (OTDR).

19 . The method as defined in claim 18 , wherein the OTDR uses a boost amplifier as a light source.

20 . The method as defined in claim 18 , wherein a transmitter used for determining the one or more parameters related to the chromatic dispersion in the span fiber is also used for determining the remote tail lengths.

21 . The method as defined in claim 20 , wherein the tunable compensator comprises:
a plurality of CD compensation fibers having dispersion values associated with the plurality of CD compensation fibers, wherein the least of the dispersion values is less than a predefined resolution and each of other dispersion values is greater than its preceding dispersion value by no more than the predefined resolution, when the dispersion values are arranged in increasing order; a tunable optical switch configurable for directing an optical signal in any of the plurality of optical channels to one of the plurality of fibers, dependent on a central wavelength of the signal; a first switch configurable for directing all signals in the plurality of optical channels to a first CD compensation fiber, in a first mode of operation, and for bypassing the first CD compensation fiber in a second mode of operation; and, the first CD compensation fiber, wherein the first switch and the tunable optical switch are connected so as to enable combining CD compensation provided by the first CD compensation fiber and CD compensation provided by any one of the plurality of CD compensation fibers.

Assignees

• Gc Photonics Inc
• Accelink Tech Co Ltd

Inventors

• Qiao Lijie
• Bu Qinlian
• Xiao Li

Classifications

• H04B10/07953 Primary

  Monitoring or measuring OSNR, BER or Q · CPC title

• H04B10/071

  using a reflected signal, e.g. using optical time domain reflectometers [OTDR] · CPC title

• H04B10/25133

  including a lumped electrical or optical dispersion compensator (H04B10/2519, H04B10/2525 takes precedence) · CPC title

• H04B10/2513

  due to chromatic dispersion · CPC title

• H04B10/6161 Primary

  Compensation of chromatic dispersion · CPC title