RECONFIGURABLE OPTICAL ADD DROP MULTIPLEXER CORE DEVICE, PROCEDURE AND SYSTEM USING SUCH DEVICE, OPTICAL LIGHT DISTRIBUTOR, AND COUPLING-RATIO ASSIGNING PROCEDURE

• US 20080260386A1
• Filed: 04/08/2008
• Published: 10/23/2008
• Est. Priority Date: 04/09/2007
• Status: Active Grant

• Current Assignee: Tellabs Operations Incorporated (Infinera Corp.)
• Original Assignee: Tellabs Operations Incorporated (Infinera Corp.)
• Inventors: Boduch, Mark E., Papakos, Kimon, Buescher, Gilbert A.
• Granted Patent: US 8,116,629 B2
• Time in Patent Office: Days
• US Class Current: 398/83
• CPC Class Codes: H04J 14/0204 Broadcast and select arrangements, e.g. with an optical splitter at the input before adding or dropping
• CPC Class Codes: H04J 14/0205 Select and combine arrangements, e.g. with an optical combiner at the output after adding or dropping
• CPC Class Codes: H04J 14/0206 Express channels arrangements
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0213 Groups of channels or wave bands arrangements
• CPC Class Codes: H04J 14/0217 Multi-degree architectures, e.g. having a connection degree greater than two
• CPC Class Codes: H04J 14/0219 Modular or upgradable architectures
• CPC Class Codes: H04J 14/0221 Power control, e.g. to keep the total optical power constant
• CPC Class Codes: H04J 14/02216 by gain equalization

Abstract

A reconfigurable optical add drop multiplexer core device includes a light distributor, a light combiner, and first and second sets of add and drop ports. The light distributor is configured to receive an optical signal along a primary input of the reconfigurable optical add drop multiplexer core device and to distribute the received optical signal along a plurality of subtending outputs. The light combiner is configured to receive optical signals along a plurality of subtending inputs, to combine the received optical signals into a combined signal, and to output the combined signal. The add and drop ports in the first set function as add and drop ports, respectively, and the add and drop ports in the second set function as both add and drop ports, respectively, and as express ports connectable to another reconfigurable optical add drop multiplexer core device.

Claims

1. A reconfigurable optical add drop multiplexer core device comprising:

a light distributor configured to receive an optical signal along a primary input of the reconfigurable optical add drop multiplexer core device and to distribute the received optical signal along a plurality of subtending outputs;

a light combiner configured to receive optical signals along a plurality of subtending inputs, to combine the received optical signals into a combined signal, and to output the combined signal; and

first and second sets of add and drop ports, the add and drop ports in the first set functioning as add and drop ports, respectively, and the add and drop ports in the second set functioning as both add and drop ports, respectively, and as express ports connectable to another reconfigurable optical add drop multiplexer core device.

2. The reconfigurable optical add drop multiplexer core device recited by claim 1, the second set of drop ports having a lower insertion loss than the first set of drop ports when the second set of drop ports function as express ports.

3. The reconfigurable optical add drop multiplexer core device recited by claim 1, the second set of add ports having a lower insertion loss than the first set of add ports when the second set of add ports function as express ports.

4. The reconfigurable optical add drop multiplexer core device recited by claim 1, further comprising an optical expansion port connectable to additional sets of add and drop ports.

5. The reconfigurable optical add drop multiplexer core device recited by claim 4, the additional sets of add and drop ports being colorless add and drop ports, respectively.

6. The reconfigurable optical add drop multiplexer core device recited by claim 4, the additional sets of add and drop ports being colored add and drop ports, respectively.

7. The reconfigurable optical add drop multiplexer core device recited by claim 1, the add and drop ports of the first and second sets being colorless add and drop ports, respectively.

8. A procedure for processing optical signals with a first reconfigurable optical add drop multiplexer core device having first and second sets of add and drop ports, the add and drop ports of the first set each being connectable to a second reconfigurable optical add drop multiplexer core device, comprising at least one of:

receiving an optical signal through one of the add ports of the first set of add ports from the second reconfigurable optical add drop multiplexer core device and providing the optical signal with a path through the first reconfigurable optical add drop multiplexer core device with less insertion loss than that provided to an optical signal received through an add port of the second set of add ports; and

outputting an optical signal through one of the drop ports of the first set of drop ports to the second reconfigurable optical add drop multiplexer core device and providing the dropped optical signal a path through the first reconfigurable optical add drop multiplexer core device with less insertion loss than that provided to the optical signal output through one of the drop ports of the second set of drop ports.

9. The procedure recited in claim 8, further comprising at least one of:

adding an optical signal to the first reconfigurable optical add drop multiplexer core device through an expansion port of the first reconfigurable optical add drop multiplexer core device that is connectable to an additional set of add ports; and

dropping an optical signal from the first reconfigurable optical add drop multiplexer core device through the expansion port of the first reconfigurable optical add drop multiplexer core device that is connectable to an additional set of drop ports.

10. The procedure recited in claim 9, the adding being performed by inputting an optical signal of a predetermined wavelength into one of the additional add ports that accepts only the predetermined wavelength, and the dropping being performed by outputting an optical signal of the predetermined wavelength into one of the additional drop ports that accepts only the predetermined wavelength

11. The procedure recited in claim 9, the adding being performed by inputting an optical signal of a predetermined wavelength into any of the additional add ports, and the dropping being performed by outputting an optical signal of the predetermined wavelength into any of the additional drop ports.

12. An optical system comprising:

a first reconfigurable optical add drop multiplexer core device having a plurality of add and drop ports; and

a second reconfigurable optical add drop multiplexer core device connected to the first reconfigurable optical add drop multiplexer core device through an add port and a drop port of the first reconfigurable optical add drop multiplexer core device.

13. The optical system recited in claim 12, the add and drop ports of the first reconfigurable optical add drop multiplexer core device comprising first and second sets of add and drop ports, the add and drop ports in the first set functioning as add and drop ports, respectively, and the add and drop ports in the second set functioning as both add and drop ports, respectively, and as express ports connectable to the second reconfigurable optical add drop multiplexer core device.

14. The optical system recited in claim 13, the second set of drop ports having a lower insertion loss than the first set of drop ports when the second set of drop ports function as express ports, and the second set of add ports having a lower insertion loss than the first set of add ports when the second set of add ports function as express ports.

15. The optical system recited in claim 13, further comprising a spur optical device comprising the second reconfigurable optical add drop multiplexer core device and connected to at least one of the add and drop ports in the second set of the first reconfigurable optical add drop multiplexer core device, the spur optical device being configured to locally add optical wavelengths to a signal exiting the drop port of the second set and to locally drop optical wavelengths from the signal forwarded to the add port of the second set.

16. The optical system recited in claim 15, further comprising:

a spur end node;

a spur main node comprising the first reconfigurable optical add drop multiplexer core device and the spur optical device, the spur optical device being configured to transmit and/or receive optical signals of a first wavelength between the spur main node and the spur end node, and

a third reconfigurable optical add drop multiplexer core device, the third reconfigurable optical add drop multiplexer core device being connected to the first reconfigurable optical add drop multiplexer core device, being in a node different from the spur main node and the spur end node, and being configured to prevent optical signals of the first wavelength received from the first reconfigurable optical add drop multiplexer core device from being transmitted from the third reconfigurable optical add drop multiplexer core device.

17. The optical system recited in claim 15, further comprising:

a first optical node comprising;

a spur end node; and

a spur main node comprising the first reconfigurable optical add drop multiplexer core device and the spur optical device, the spur optical device being configured to transmit and/or receive optical signals of a first wavelength between the spur main node and the spur end node; and

a second optical node comprising;

third and fourth reconfigurable optical add drop multiplexer core devices, the third reconfigurable optical add drop multiplexer core device being connected to the first reconfigurable optical add drop multiplexer core device and to the fourth reconfigurable optical add drop multiplexer core device, the fourth reconfigurable optical add drop multiplexer core device being configured to prevent optical signals of the first wavelength transmitted between the spur main node and the spur end node of the first optical node from being transmitted out of the second optical node.

18. The optical system recited in claim 12, the first reconfigurable optical add drop multiplexer core device further comprising an optical expansion port connectable to additional sets of add and drop ports.

19. An optical light distributor comprising:

a primary input;

an express output;

a plurality of subtending outputs; and

a light-directing device configured to perform the following operations on a wavelength arriving on the primary input;

direct the entire optical power of the wavelength only to the express output;

direct the entire optical power of the wavelength only to one of the subtending outputs; and

direct a portion of the optical power of the wavelength to only one of the subtending outputs and a portion of the optical power of the wavelength to the express output.

20. The optical light distributor recited by claim 19, further comprising a light distributor device configured to receive a multiplexed optical signal of a plurality of different wavelengths and to transmit optical signals of single wavelengths on different outputs thereof, the outputs of the light distributor device being further directed by the light-directing device.

21. The optical light distributor recited by claim 20, the light directing device comprising a plurality of switches, each of which is connected to one of the outputs of the light distributor device.

22. A dense wavelength division multiplexing optical add/drop optical node comprising:

a first set of optical couplers;

a second set of optical couplers; and

a third set of optical couplers, the output of the first set of optical couplers and part of the output of the second set of optical couplers being input into the third set of optical couplers, the coupling ratios for the first set of optical couplers being equal among all the inputs of each optical coupler in the first set, the coupling ratios for the second set of optical couplers being such that the power level of an optical wavelength output therefrom along a path directed to a drop port of a first reconfigurable optical add drop multiplexer core device in the node is the minimum required power for optical wavelengths dropped from the first reconfigurable optical add drop multiplexer core device, and the coupling ratios for the third set of optical couplers maximizing the power level of the optical wavelength exiting the third set of optical couplers with the lowest optical power.

23. The node recited by claim 22, the second set of optical couplers including a set of 1-to-2, optical-power-divider-type light distributors within a light distributor device configured to select any of the following operations:

directing the entire optical power of the wavelength only to an express output thereof;

directing the entire optical power of the wavelength only to one of the subtending outputs thereof; and

directing a portion of the optical power of the wavelength to only one of the subtending outputs and a portion of the optical power of the wavelength to the express output.

24. The node recited by claim 22, the first set of optical couplers including an optical coupler that combines the signals from add ports contained on a port expansion module.

25. The node recited by claim 22, the first set of optical couplers including a first coupler that combines all the signals of add ports operable as express ports, and a second coupler which combines all the signals of add ports that do not operate as express ports.

26. The node recited by claim 22, the third set of optical couplers residing on the first reconfigurable optical add drop multiplexer core device and processes:

signals from add ports of the first reconfigurable optical add drop multiplexer core device;

a signal from an express output port of a second reconfigurable optical add drop multiplexer core device; and

a signal from an expansion output port of an expansion module attached to the first reconfigurable optical add drop multiplexer core device.

27. A procedure for assigning coupling ratios for first, second, and third sets of optical couplers within a dense wavelength division multiplexing optical add/drop node, the output of the first set of optical couplers and part of the output of the second set of optical couplers being input into the third set of optical couplers, the procedure comprising:

choosing the coupling ratios for the first set of optical couplers to be equal among all the inputs of each optical coupler in the first set;

choosing the coupling ratios for the second set of optical couplers such that the power level of an optical wavelength output therefrom along a path directed to a drop port of a first reconfigurable optical add drop multiplexer core device in the node is the minimum required power for optical wavelengths dropped from the first reconfigurable optical add drop multiplexer core device; and

choosing the coupling ratios for the third set of optical couplers to maximize the power level of the optical wavelength exiting the third set of optical couplers with the lowest optical power.