DISPERSION SLOPE COMPENSATION AND DISPERSION MAP MANAGEMENT SYSTEMS AND METHODS

• US 20100329695A1
• Filed: 06/25/2009
• Published: 12/30/2010
• Est. Priority Date: 06/25/2009
• Status: Active Grant

• Current Assignee: Ciena Corporation
• Original Assignee: Ciena Corporation
• Inventors: SRIDHAR, Balakrishnan
• Granted Patent: US 8,606,108 B2
• Time in Patent Office: Days
• US Class Current: 398/159
• CPC Class Codes: H04B 10/25253 with dispersion management, i.e. using a combination of different kind of fibres in the transmission system

Abstract

The present disclosure relates to dispersion slope compensation and dispersion map management systems and methods in an optical network utilizing a reconfigurable optical add-drop multiplexer (ROADM) with a plurality of different values of dispersion compensation modules (DCMs). The DCMs form a dispersion compensation ladder at certain intermediate nodes in the optical network to provide dispersion slope compensation and dispersion map management. The reconfigurable routing structure of the ROADM enables these intermediate nodes to route individual wavelengths to any one of the DCMs as required for the particular path of the wavelength. Advantageously, the present invention removes the requirement for banded compensation at receiver nodes and allows for dispersion map management at intermediate points along a fiber route as opposed to bulk compensation at the receiver.

Claims

1. A dispersion compensation node, comprising:

a reconfigurable input device;

a reconfigurable output device; and

a plurality of dispersion compensation elements each connected to the reconfigurable input device and the reconfigurable output device, wherein the plurality of dispersion compensation elements comprise different dispersion compensation values.

2. The dispersion compensation node of claim 1, wherein the reconfigurable input device and the reconfigurable output device are configured to route a wavelength to one of the plurality of dispersion compensation elements responsive to compensation required for the wavelength;

and

wherein the reconfigurable input device and the reconfigurable output device are further configured to dynamically adjust the compensation required using feedback from one of a tunable dispersion compensator and either a bit-error rate (BER) or Q measurement at a receiver.

3. The dispersion compensation node of claim 2, wherein the reconfigurable input device comprises a de-multiplexer configured to receive an input comprising one or more wavelengths and to split copies of the one or more wavelengths to the plurality of dispersion compensation elements;

and

wherein the reconfigurable output device comprises a wavelength selective switch configured to receive inputs of the one or more wavelengths from each of the plurality of dispersion compensation elements and to selectively couple the one or more wavelengths to an output.

4. The dispersion compensation node of claim 2, wherein the reconfigurable input device comprises a wavelength selective switch configured an input comprising one or more wavelengths and to selectively couple each of the one or more wavelengths to the plurality of dispersion compensation elements based on an amount of compensation needed for each of the one or more wavelengths;

and

a multiplexer configured to receive inputs from each of the plurality of dispersion compensation elements and to couple the inputs to an output.

5. The dispersion compensation node of claim 2, wherein the plurality of dispersion compensation elements comprise a dispersion compensation ladder such that each of the different dispersion compensation values for the plurality of dispersion compensation elements are in one of uniform and non-uniform steps.

6. The dispersion compensation node of claim 5, wherein a step size for the uniform and non-uniform steps is responsive to a number of ports on the reconfigurable input device and the reconfigurable output device.

7. The dispersion compensation node of claim 2, further comprising:

at least one wavelength that is dropped and added through the reconfigurable input device and the reconfigurable output device.

8. The dispersion compensation node of claim 2, further comprising:

a computer configured to execute a planning tool to determine the different dispersion compensation values responsive to fiber types and wavelength routing.

9. The dispersion compensation node of claim 2, further comprising:

a plurality of dense wave division multiplexed wavelengths traversing the reconfigurable input device, the plurality of dispersion compensation elements, and the reconfigurable output device;

wherein at least one of the plurality of dense wave division multiplexed wavelengths comprises a different path from at least one other of the plurality of dense wave division multiplexed wavelengths such that the at least one and the at least one other traverse different elements of the plurality of dispersion compensation elements.

10. An optical network, comprising:

a plurality of nodes, wherein at least one of the plurality of nodes comprises a reconfigurable optical add-drop multiplexer configured with a dispersion compensation ladder comprising a plurality of dispersion compensation elements of differing values disposed between inputs and outputs of the reconfigurable optical add-drop multiplexer; and

an algorithm configured to route wavelengths traversing the reconfigurable optical add-drop multiplexer configured with the dispersion compensation ladder to one of the plurality of dispersion compensation elements based on an amount of dispersion compensation required for each of the wavelengths.

11. The optical network of claim 10, wherein the reconfigurable optical add-drop multiplexer comprises:

a de-multiplexer configured to receive an input comprising one or more wavelengths and to split copies of the one or more wavelengths to the plurality of dispersion compensation elements; and

a wavelength selective switch configured to receive inputs of the one or more wavelengths from each of the plurality of dispersion compensation elements and to selectively couple the one or more wavelengths to an output.

12. The optical network of claim 10, wherein the reconfigurable optical add-drop multiplexer comprises:

a wavelength selective switch configured an input comprising one or more wavelengths and to selectively couple each of the one or more wavelengths to the plurality of dispersion compensation elements based on an amount of compensation needed for each of the one or more wavelengths; and

a multiplexer configured to receive inputs from each of the plurality of dispersion compensation elements and to couple the inputs to an output.

13. The optical network of claim 10, wherein the dispersion compensation ladder is configured such that each of the plurality of dispersion compensation elements comprises different dispersion compensation values in one of uniform and non-uniform steps.

14. The optical network of claim 13, wherein a step size for the uniform and non-uniform steps is responsive to a number of ports on reconfigurable optical add-drop multiplexer.

15. The optical network of claim 10, further comprising:

at least one wavelength that is dropped and added at the reconfigurable optical add-drop multiplexer.

16. The optical network of claim 10, further comprising:

a computer configured to execute a planning tool to determine different dispersion compensation values for the dispersion compensation ladder responsive to fiber types and wavelength routing; and

wherein the algorithm is configured to dynamically adjust the amount of dispersion compensation required using feedback from one of a tunable dispersion compensator and either a bit-error rate (BER) or Q measurement at a receiver.

17. The optical network of claim 10, further comprising:

a plurality of dense wave division multiplexed wavelengths traversing the reconfigurable optical add-drop multiplexer;

wherein at least one of the plurality of dense wave division multiplexed wavelengths comprises a different path from at least one other of the plurality of dense wave division multiplexed wavelengths such that the at least one and the at least one other traverse different elements of the plurality of dispersion compensation elements.

18. A method of dispersion compensation in an optical network, comprising:

configuring the optical network with at least one reconfigurable optical add-drop multiplexer node comprising a dispersion compensation ladder comprising a plurality of dispersion compensation elements of differing values disposed between inputs and outputs of the reconfigurable optical add-drop multiplexer;

adding a wavelength that traverses the at least one reconfigurable optical add-drop multiplexer node;

determining dispersion compensation required for the wavelength responsive to a path of the wavelength in the optical network; and

configuring the at least one reconfigurable optical add-drop multiplexer node to route the wavelength to one of the plurality of dispersion compensation elements responsive to the dispersion compensation required.

19. The method of claim 18, further comprising:

adding a second wavelength that traverses the at least one reconfigurable optical add-drop multiplexer node, wherein the second wavelength comprises a different path from the path of the wavelength;

determining dispersion compensation required for the second wavelength responsive to the different path of the second wavelength in the optical network; and

configuring the at least one reconfigurable optical add-drop multiplexer node to route the second wavelength to one of the plurality of dispersion compensation elements responsive to the dispersion compensation required.

20. The method of claim 18, further comprising:

reconfiguring a second wavelength in the optical network such that the second wavelength traverses the at least one reconfigurable optical add-drop multiplexer node;

determining dispersion compensation required for the second wavelength responsive to a path of the second wavelength in the optical network; and

configuring the at least one reconfigurable optical add-drop multiplexer node to route the second wavelength to one of the plurality of dispersion compensation elements responsive to the dispersion compensation required.