Optical power and chromatic dispersion equalization system

Patent metadata

Field	Value
Publication number	US-10225016-B1
Application number	US-201615195983-A
Country	US
Kind code	B1
Filing date	Jun 28, 2016
Priority date	Jun 28, 2016
Publication date	Mar 5, 2019
Grant date	Mar 5, 2019

Abstract

Wavelength multiplexed optical communication systems include a channeled chromatic dispersion compensator coupled to receive modulated optical beams associated with a plurality of optical channels at respective communication wavelengths. The channeled chromatic dispersion compensator applies independently selected dispersion compensations to each of the optical channels by identifying a dispersion compensation associated with a preferred bit error rate, inter-symbol interference, or other signal quality metric, or determined using optical fiber properties such as dispersion slope and zero dispersion wavelength. Chromatic dispersion compensation can be coupled with channel power equalization, and can be performed at a receiver or a transmitter or in the middle of a fiber span.

First claim

What is claimed is:

1. A transmitter system for optical fiber communications, comprising:
a plurality of optical transmitters that produce modulated optical beams at respective wavelengths;
a fiber optic multiplexer optically coupled to each of the optical transmitters so as to receive the modulated optical beams from each of the plurality of optical transmitters and produce a combined optical output beam;
a channeled dispersion compensation system comprising an optical switch and a channeled dispersion compensator coupled to the fiber optical multiplexer, wherein the optical switch selects the combined optical output beam or a combined optical input beam comprising modulated optical beams at the respective wavelengths, wherein the channeled dispersion compensator is situated to apply an individually selectable chromatic dispersion compensation to each of the modulated optical beams at the respective wavelengths in the selected optical beam, and produce a combined, dispersion-compensated and power equalized optical beam; and
a processor coupled to the channeled dispersion compensator and operable to select the individually selectable chromatic dispersion compensations associated with the selected optical beam.

2. The transmitter system of claim 1 , further comprising an optical amplifier coupled to receive the combined optical output beam from the fiber optical multiplexer and deliver the combined optical output beam to the channeled dispersion compensator.

3. The transmitter system of claim 1 , wherein the channeled dispersion compensator includes a grating and a liquid crystal array on a silicon substrate, wherein the grating is coupled to receive the selected optical beam and direct beam portions at the respective wavelengths to corresponding elements of the liquid crystal array.

4. The transmitter system of claim 3 , wherein the processor applies dispersion compensations based on one or both of channel bit error rates or inter-symbol interference.

5. A dispersion compensation system for optical communications, comprising:
an optical switch coupled to select an input beam that comprises optical beams at each of a plurality of wavelengths or an output beam that comprises optical beams at each of the plurality of wavelengths;
a channeled dispersion compensator that applies individually selectable dispersions to each of the plurality of wavelengths in the selected optical beam;
a processor coupled to the channeled dispersion compensator so as to select a preferred dispersion compensation for the optical beams at each of the plurality of wavelengths in the selected optical beam, wherein the channeled dispersion compensator applies dispersion compensations to the optical beams at each of the plurality of wavelengths.

6. The dispersion compensation system of claim 5 , wherein
the preferred dispersion compensation for each of the optical beams is based on bit error rate or inter-symbol interference.

7. The dispersion compensation system of claim 5 , wherein the channeled dispersion compensator includes a grating and a liquid crystal modulator array, wherein the grating is coupled to receive the selected optical beam and direct beam portions at respective wavelengths of the plurality of wavelengths to corresponding sets of elements of the liquid crystal modulator array, wherein the processor is coupled to the sets of elements so as to select one or more dispersion compensations at each of the plurality of wavelengths.

8. The dispersion compensation system of claim 7 , wherein the processor is coupled to the sets of elements of the liquid crystal modulator array to establish optical beam powers at each of the plurality of wavelengths so as to select a preferred optical power for the optical beams at each of the plurality of wavelengths in the selected optical beam.

9. The dispersion compensation system of claim 7 , further comprising an optical multiplexer having a plurality of multiplexer inputs and a multiplexer output, wherein the multiplexer output is optically coupled to the channeled dispersion compensator.

10. The dispersion compensation system of claim 7 , further comprising an optical multiplexer having a plurality of multiplexer inputs and a multiplexer output and an optical amplifier, wherein the multiplexer output is optically coupled to the optical amplifier and the optical amplifier is optically coupled to the channel dispersion compensator.

11. The dispersion compensation system of claim 7 , wherein the channeled dispersion compensator includes an optical fiber situated to receive the input beam and deliver an output beam that is dispersion compensated at each of the plurality of wavelengths.

12. The dispersion compensation system of claim 5 , wherein the processor selects a preferred optical power for the optical beams in the selected optical beam at each of the plurality of wavelengths so as to establish a power equalized and dispersion compensated combined optical beam.

13. An optical communication network, comprising:
a plurality of transceivers that produce corresponding modulated optical beams, wherein each transceiver has an associated channel wavelength;
an optical multiplexer coupled to the plurality of transceivers so as to couple the modulated optical beams from the plurality of transceivers to a single optical fiber as a combined transmitted beam;
a wavelength monitor;
an optical switch that selects one of the combined transmitted beam or a combined received beam comprising modulated optical beams at the associated channel wavelengths and couples a portion of the selected optical beam to the wavelength monitor;
a processor coupled to the wavelength monitor and configured to select at least one preferred dispersion compensation for the selected optical beam; and
a channeled chromatic dispersion (CD) compensator coupled to receive the selected optical beam and independently CD compensate portions of the selected optical beam corresponding to each of the modulated optical beams and produce a CD compensated combined optical beam based on the preferred dispersion compensation.

14. The optical communication network of claim 13 , further comprising an optical amplifier situated to receive the combined transmitted beam or the combined received beam and direct a corresponding amplified combined beam to the channeled CD compensator.

15. The optical communication network of claim 13 , wherein the channeled CD compensator independently adjusts optical powers in the selected optical beam corresponding to each of the modulated optical beams so as to produce a CD compensated, power equalized combined optical beam.

16. The optical communication network of claim 13 , further comprising a first optical amplifier and a second optical amplifier, wherein the first optical amplifier is situated to receive the combined transmitted beam and direct an amplified combined beam to the channeled CD compensator, and the second optical amplifier is situated to receive the CD compensated amplified combined beam from the channeled CD compensator.

17. The optical communication network of claim 13 , wherein the selected optical beam is the combined transmitted beam so that the CD compensated combined optical beam is a transmitted CD compensated combined optical beam, further comprising an optical fiber link situated to deliver the transmitted CD compensated combined optical beam to remote receivers.

18. The optical communication network of claim 13 , wherein the channeled CD compensator independently compensates the portions of the selected optical beam corresponding t

Assignees

• Amazon Tech Inc

Inventors

• Khaleghi Salman
• Abbess Emily
• Rodenchuk Christopher
• Mahdi Hayder Alaa Adel
• Harrison Robert
• Connolly Matt

Classifications

• H04J14/0256

  at the optical channel layer · CPC title

• H04B2210/258

  treating each wavelength or wavelength band separately · CPC title

• H04B10/07951

  Monitoring or measuring chromatic dispersion or PMD · CPC title

• H04B10/25133 Primary

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

• H04B10/0797

  Monitoring line amplifier or line repeater equipment · CPC title