Wavelength-selective cross-connect device having a variable number of common ports

• US 9,225,458 B2
• Filed: 12/20/2013
• Issued: 12/29/2015
• Est. Priority Date: 12/20/2013
• Status: Active Grant

• Current Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation)
• Inventors: Darling, Mike J., Cheng, Lu, Ehrlich, Jeffrey E.
• Primary Examiner(s): SINGH, DALZID E
• Application Number:
  US14/135,632
• Publication Number:
  US 20150180603A1
• Time in Patent Office: 739 Days
• Field of Search: 398/45, 398 48- 50, 398/55, 398/56, 398/82, 398/87, 398/88
• US Class Current: 1/1
• CPC Class Codes: H04B 10/27 Arrangements for networking
• CPC Class Codes: H04J 14/02 Wavelength-division multiplex systems
• CPC Class Codes: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0307 Multiplexers; Demultiplexers
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0016 using wavelength multiplexing or demultiplexing
• CPC Class Codes: H04Q 2011/0022 using fibre gratings
• CPC Class Codes: H04Q 2011/0026 using free space propagation (e.g. lenses, mirrors)
• CPC Class Codes: H04Q 2011/003 using switches based on microelectro-mechanical systems [MEMS]
• CPC Class Codes: H04Q 2011/0035 using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical

Abstract

A configurable wavelength-selective cross-connect (WSXC) device having an array of optical ports in which at least some of the ports are configurable to operate as common ports or as plural ports. The configurable WSXC device includes a MEMS mirror array whose mirrors are tiltable in a manner that enables, e.g., reconfigurations of the configurable WSXC device that result in a change of the number of common ports therein. In one possible configuration, the configurable WSXC device can operate as 1×M₁ wavelength-selective switch, where M₁+1≦P, and P is the total number of optical ports in the array of optical ports. In another possible configuration, the configurable WSXC device can operate as a bank of n 1×M₂ wavelength-selective switches, where n is a positive integer greater than one, and n(M₂+1)≦P.

Claims

1. An apparatus comprising:

a reconfigurable wavelength-selective optical router; and

a MEMS mirror array having a plurality of individually movable mirrors, wherein each of the movable mirrors is configured to receive light from or direct light to a respective one optical port in an array of optical ports and is configurable to optically couple the optical ports in at least a first configuration and a second configuration, wherein;

in the first configuration, the array of optical ports has a single common port and a plurality of plural ports that are configured as a common port and respective plural ports of a first wavelength-selective switch; and

in the second configuration, the array of optical ports has a first common port, a second common port, a first plurality of plural ports, and a second plurality of plural ports, wherein;

the first common port and the first plurality of plural ports are configured as a common port and respective plural ports of a second wavelength-selective switch; and

the second common port and the second plurality of plural ports are configured as a common port and respective plural ports of a third wavelength-selective switch.

2. The apparatus of claim 1, wherein the second wavelength-selective switch and the third wavelength-selective switch have no optical ports in common.

3. The apparatus of claim 1, wherein:

the first wavelength-selective switch is a 1×

N₁ wavelength-selective switch, wherein N₁+1≦

P, where P is a total number of ports in the array of optical ports;

the second wavelength-selective switch is a 1×

N₂ wavelength-selective switch; and

the third wavelength-selective switch is a 1×

N₃ wavelength-selective switch, wherein N₂+N₃+2≦

P.

4. The apparatus of claim 3, wherein N₂=N₃.

5. The apparatus of claim 1, wherein an optical port that is configured to operate as the single common port in the first configuration is configurable to operate as one of the first and second common ports in the second configuration.

6. The apparatus of claim 1, wherein an optical port that is configured to operate as one of the plural ports in the first configuration is configurable to operate as one of the first and second common ports in the second configuration.

7. The apparatus of claim 1, wherein, in a third configuration, the array of optical ports has a set of three common ports and three non-overlapping pluralities of plural ports, wherein:

a first common port in said set of three common ports and a first of the three non-overlapping pluralities of plural ports are configured as a common port and plural ports, respectively, of a fourth wavelength-selective switch;

a second common port in said set of three common ports and a second of the three non-overlapping pluralities of plural ports are configured as a common port and plural ports, respectively, of a fifth wavelength-selective switch; and

a third common port in said set of three common ports and a third of the three non-overlapping pluralities of plural ports are configured as a common port and plural ports, respectively, of a sixth wavelength-selective switch.

8. The apparatus of claim 7, wherein:

the fourth wavelength-selective switch is a 1×

N₄ wavelength-selective switch;

the fifth wavelength-selective switch is a 1×

N₅ wavelength-selective switch; and

the sixth wavelength-selective switch is a 1×

N₆ wavelength-selective switch, wherein N₄+N₅+N₆+3≦

P, where P is a total number of ports in the array of optical ports.

9. The apparatus of claim 1, wherein the reconfigurable wavelength-selective optical router comprises:

a beam-steering device optically coupled to the MEMS mirror array; and

a spectrally dispersive element optically coupled between the MEMS mirror array and the beam-steering device in a manner that enables the beam-steering device to steer any of a plurality of carrier wavelengths received from a respective common port of any of the first, second, and third wavelength-selective switches to any plural port in the respective plurality of plural ports.

10. The apparatus of claim 9, wherein, in the second configuration, the movable mirrors in the MEMS mirror array are individually tilted to cause the spectrally dispersive element to:

disperse light corresponding to the second wavelength-selective switch in a dispersion direction across the beam-steering device at a first position; and

disperse light corresponding to the third wavelength-selective switch in said dispersion direction across the beam-steering device at a second position that is offset with respect to the first position.

11. The apparatus of claim 9, wherein the beam-steering device comprises a pixelated liquid-crystal-on-silicon micro-display.

12. The apparatus of claim 9, wherein the beam-steering device comprises a two-dimensional pixelated array of movable mirrors.

13. The apparatus of claim 9, further comprising:

a first optics set configured to image a mirror plane of the MEMS mirror array onto the spectrally dispersive element; and

a second optics set configured to convert angular dispersion of the plurality of carrier wavelengths generated by the spectrally dispersive element into a spatial separation of the plurality of carrier wavelengths at the beam-steering device.

14. The apparatus of claim 13, wherein at least one of the first and second optics sets includes at least one cylindrical lens.

15. The apparatus of claim 1, wherein the array of optical ports is a linear array.

16. The apparatus of claim 1, further comprising a configuration controller configured to change tilt angles of the mirrors MEMS mirror array to convert one of the first and second configurations into the other of the first and second configurations.

17. The apparatus of claim 1, wherein, in the second configuration:

one of the first common port and the second common port is configured to operate as an input port; and

the other one of the first common port and the second common port is configured to operate as an output port.

18. A method of configuring a wavelength-selective cross-connect (WSXC) device, the method comprising:

sorting P optical ports of the WSXC device into n non-overlapping sets of ports, where P is a positive integer greater than five and n is a positive integer greater than one;

in each of said n non-overlapping sets of ports, designating one common port and a respective plurality of plural ports;

individually tilting tiltable mirrors in a MEMS mirror array of the WSXC device to cause a spectrally dispersive element of the WSXC device to disperse light across a beam-steering device of the WSXC device at n different positions that are offset from one another in a direction orthogonal to a dispersion direction such that each position is configured to receive light from a respective one of the n non-overlapping sets of ports; and

reconfiguring the WSXC device to change the number n.

19. The method of claim 18, further comprising:

configuring the WSXC device to operate as a bank of n wavelength-selective switches, each being configured to route light between the optical ports of a respective one of the n non-overlapping sets of ports.

20. An apparatus, comprising:

an optical routing device that comprises an array of MEMS mirrors and a wavelength-selective optical router being optically connected to an array of P optical ports by the array of MEMS mirrors; and

wherein the MEMS mirrors are configurable to connect the optical ports of the array of the P optical ports to the wavelength-selective optical router in different first and second configurations, the optical routing device being configured to operate some of the optical ports of the array of the P optical ports as a 1×

N₁ first optical wavelength-selective switch in the first configuration with N₁ being smaller than P and greater than one, and being configured to operate some of the optical ports of the array of the P optical ports as a 1×

N₂ second optical wavelength-selective switch and a 1×

N₃ third optical wavelength-selective switch in the second configuration with the integers N₂ and N₃ each being greater than one and where N₂+N₃+2≦

P.

21. The apparatus of claim 20, wherein the integers N₂ and N₃ are each greater than or equal to (P−

2)/4.

22. The apparatus of claim 20, further comprising an electronic controller connected to operate the array of MEMS mirrors, the electronic controller being capable of operating the MEMS mirrors such that the optical ports of the array of the P optical ports and the wavelength-selective optical router are capable of being connected in any of the first and second configurations.

23. The apparatus of claim 20, further comprising a reconfigurable optical add-drop multiplexer, the reconfigurable optical add-drop multiplexer including the optical routing device.

24. The apparatus of claim 20, wherein the MEMS mirrors are configured to perform tilt motions.

25. The apparatus of claim 20, wherein the wavelength-selective optical router includes a second array of MEMS mirrors or an array of liquid-crystal-on-semiconductor elements.