Contentionless N×M wavelength cross connect

• US 9,432,750 B1
• Filed: 04/21/2014
• Issued: 08/30/2016
• Est. Priority Date: 04/19/2013
• Status: Active Grant

• Current Assignee: Wavexing, Inc.
• Original Assignee: Wavexing, Inc.
• Inventors: Li, Fenghua
• Primary Examiner(s): Bello, Agustin
• Application Number:
  US14/257,846
• Time in Patent Office: 862 Days
• Field of Search: 398 82- 88
• US Class Current: 1/1
• CPC Class Codes: G02B 6/29383 Adding and dropping
• CPC Class Codes: G02B 6/29394 Compensating wavelength dispersion G02B6/29376 takes precedence; dispersion compensated optical transmission systems H04B10/2507
• CPC Class Codes: G02B 6/32 having lens focusing means positioned between opposed fibre ends with lens being an integral part of the single fibre end G02B6/262
• CPC Class Codes: G02B 6/3534 the optical element being diffractive, i.e. a grating
• CPC Class Codes: G02B 6/3546 NxM switch, i.e. a regular array of switches elements of matrix type constellation
• CPC Class Codes: G02B 6/356 in an optical cross-connect device, e.g. routing and switching aspects of interconnecting different paths propagating different wavelengths to (re)configure the various input and output links switching polarized beams G02B6/3594; power equalizers G02B6/356 and G02B6/3594; path selecting means H04Q11/0001
• CPC Class Codes: G02F 1/0136 for the control of polarisation, e.g. state of polarisation [SOP] control, polarisation scrambling, TE-TM mode conversion or separation G02F1/0353 takes precedence
• CPC Class Codes: G02F 1/1326 Liquid crystal optical waveguides or liquid crystal cells specially adapted for gating or modulating between optical waveguides
• 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 14/021 Reconfigurable arrangements, e.g. reconfigurable optical add/drop multiplexers [ROADM] or tunable optical add/drop multiplexers [TOADM]
• CPC Class Codes: H04J 14/02122 Colourless, directionless or contentionless [CDC] arrangements
• 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
• CPC Class Codes: H04J 14/06 Polarisation multiplex systems
• CPC Class Codes: H04Q 11/0005 Switch and router aspects
• CPC Class Codes: H04Q 2011/0015 using splitting combining
• CPC Class Codes: H04Q 2011/0016 using wavelength multiplexing or demultiplexing
• CPC Class Codes: H04Q 2011/0022 using fibre gratings
• CPC Class Codes: H04Q 2011/0035 using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical
• CPC Class Codes: H04Q 2011/0041 Optical control
• CPC Class Codes: H04Q 2011/0058 : Crossbar; Matrix

Abstract

Technology for a contentionless N×M wavelength cross connect (WXC) device is disclosed herein. The WXC device includes multiple input and output wavelength dispersive elements and a cross connect assembly. The cross connect assembly includes multiple rows of incoming ports. For each individual wavelength of different wavelengths, split optical beams of the individual wavelength from the input wavelength dispersive elements reach a row of incoming ports corresponding to the individual wavelength. The cross connect assembly further includes transmissive active switching elements and multiple rows of outgoing ports. The transmissive active switching elements configured to dynamically establish at least one optical path between an incoming port within the row of incoming ports corresponding to the individual wavelength and an outgoing port within a row of output ports corresponding to the individual wavelength.

Claims

1. A wavelength cross connect (WXC) device comprising:

N input ports for receiving input optical beams;

M output ports for transmitting output optical beams;

N input wavelength dispersive elements, each of the N input wavelength dispersive elements separating by diffraction one of the input optical beams into L split optical beams at L wavelength channels;

a cross connect assembly having at least N×

L incoming ports, multiple transmissive active switching elements, and at least M×

L outgoing ports, wherein each of the N×

L incoming ports belongs to one of the L wavelength channels, and each of the M×

L outgoing ports belongs to one of the L wavelength channels, wherein the cross connect assembly includes attenuation components for attenuating the split optical beams;

the N×

L input port receiving the N×

L split optical beams from the N input wavelength dispersive elements;

the transmissive active switching elements configured to dynamically control optical paths between the N×

L incoming ports and the M×

L outgoing ports by dynamically changing directions of the optical paths such that anyone of the incoming ports of an individual wavelength channel of the L wavelength channels can establish an optical path within a common horizontal wavelength plane with anyone of the outgoing ports of the individual wavelength channel at a moment, wherein for an individual wavelength channel among the L wavelength channels, the split optical beams of the individual wavelength channel have a common wavelength and travel in a common horizontal wavelength plane corresponding to the individual wavelength channel; and

M output wavelength dispersive elements, each of the M output wavelength dispersive elements receiving L split optical beams from some of the M×

L outgoing ports and combining the L received split optical beams into one of the output optical beams.

2. The wavelength cross connect device of claim 1, wherein the input wavelength dispersive elements form a single input wavelength dispersive component, and the output wavelength dispersive elements form a single input wavelength dispersive component.

3. The wavelength cross connect device of claim 1, wherein the split optical beams of a particular wavelength channel transport in the cross connect assembly without interference by other split optical beams of the particular wavelength channel.

4. The wavelength cross connect device of claim 1, further comprising:

incoming optical lens for guiding the split optical beams from the input wavelength dispersive elements to the incoming ports of the cross connect assembly; and

outgoing optical lens for guiding the split optical beams from the outgoing ports of the cross connect assembly to the outgoing wavelength dispersive elements.

5. The wavelength cross connect device of claim 1, wherein the transmissive active switching elements comprises active liquid crystal based polarization grating cells.

6. The wavelength cross connect device of claim 1, wherein the transmissive active switching elements comprises combinations of active liquid crystal based polarization grating cells and passive liquid crystal mesogen polarization grating cells.

7. The wavelength cross connect device of claim 1, wherein the transmissive active switching elements comprises birefringent crystal.

8. The wavelength cross connect device of claim 1, wherein the transmissive active switching elements comprises active matrix thin-film transistor liquid crystal cells.

9. The wavelength cross connect device of claim 1, wherein the N input ports comprise collimators for collimating the input optical beams, and the M output ports comprise collimators for collimating the output optical beams.

10. An optical switching device comprising:

multiple input wavelength dispersive elements, each of the input wavelength dispersive elements receiving an input optical beam and splitting the input optical beam into multiple split optical beams of different wavelengths;

beam expansion units for expanding beam angles of the input optical beams;

a cross connect assembly including multiple rows of incoming ports, each row of incoming ports including a plurality of incoming ports, wherein for each individual wavelength of the different wavelengths, the split optical beams of the individual wavelength from the input wavelength dispersive elements reach a row of incoming ports corresponding to the individual wavelength by travelling in a horizontal wavelength plane corresponding to the individual wavelength;

the cross connect assembly further including active switching elements and multiple rows of outgoing ports, each row of outgoing ports including a plurality of outgoing ports, wherein the active switching elements configured to dynamically establish at least one optical path within the horizontal wavelength plane between an incoming port within the row of incoming ports corresponding to the individual wavelength and an outgoing port within a row of output ports corresponding to the individual wavelength by dynamically changing directions of optical paths of the split optical beams; and

multiple output wavelength dispersive elements, each of the output wavelength dispersive elements combining some of the split optical beams into an output optical beam.

11. The optical switching device of claim 10, wherein the output optical beam contain split optical beams from more than one different input optical beams.

12. The optical switching device of claim 10, further comprising:

input collimators for collimating the input optical beams; and

output collimators for collimating the output optical beams.

13. The optical switching device of claim 10, further comprising:

polarization diverse elements for polarizing the input optical beams.

14. The optical switching device of claim 10, wherein the active switching elements comprise transmissive active switching elements.

15. The optical switching device of claim 10, wherein the active switching elements comprise at least one reflective active switching elements.