Polarization diverse wavelength selective switch

• US 10,461,878 B2
• Filed: 04/08/2017
• Issued: 10/29/2019
• Est. Priority Date: 07/19/2012
• Status: Active Grant

• Current Assignee: II-VI Delaware, Inc. (Coherent Corp.)
• Original Assignee: Finisar Corporation (II-VI Incorporated)
• Inventors: Frisken, Steven James
• Primary Examiner(s): Jacob, Oommen
• Application Number:
  US15/482,739
• Publication Number:
  US 20170214482A1
• Time in Patent Office: 934 Days
• Field of Search: 398 48, 398 45, 398 43, 398 47
• CPC Class Codes: G02B 6/2931 Diffractive element operating in reflection
• CPC Class Codes: G02B 6/29373 utilising a bulk dispersive element, e.g. prism
• CPC Class Codes: G02B 6/3512 the optical element being reflective, e.g. mirror
• CPC Class Codes: G02B 6/3556 NxM switch, i.e. regular arrays 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: H04J 14/0212 using optical switches or wavelength selective switches [WSS]
• CPC Class Codes: H04J 14/0221 Power control, e.g. to keep the total optical power constant
• CPC Class Codes: H04J 14/06 Polarisation multiplex systems
• CPC Class Codes: H04Q 11/0003 Details
• 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 2011/0035 using miscellaneous components, e.g. circulator, polarisation, acousto/thermo optical
• CPC Class Codes: H04Q 2011/0039 Electrical control

Abstract

Described herein is a wavelength selective switch (WSS) type optical switching device (1) configured for switching input optical beams from input optical fiber ports (3, 5 and 7) to an output optical fiber port (9). Device (1) includes a wavelength dispersive grism element (13) for spatially dispersing the individual wavelength channels from an input optical beam in the direction of a second axis (y-axis). The optical beams propagate from input ports (3, 5 and 7) in a forward direction and are reflected from a liquid crystal on silicon (LCOS) device (11) in a return direction to output port (9). The input optical beams are transmitted through a port selecting module (21), which provides polarization diversity to device (1) and provides capability to restrict optical beams returning from LCOS device (11) from being coupled back into input ports (3, 5 and 7).

Claims

1. A dual-source wavelength selective switch comprising:

a) a first source comprising a first plurality of ports and carrying a first group of beams and a second source comprising a second plurality of ports and carrying a second group of beams;

b) a first and second polarizing port selecting module element, the first source transmitting a plurality of beams from the first group of beams to the first polarizing port selecting module element and the second source transmitting a plurality of beams from the second group of beams to the second polarizing port selecting module element, the first and second polarizing port selecting module elements generating a respective first and second output beam that are orthogonally polarized;

c) a first beam confining module coupled to the first and second polarizing port selecting module elements, the first beam confining module confining and realigning the first and second output beam that are orthogonally polarized along a direction of propagation to generate confined and realigned orthogonally polarized beams;

d) a collimating element positioned in the path of the confined and realigned orthogonally polarized beams;

e) a wavelength dispersive element positioned in the path of the confined and realigned orthogonally polarized beams for spatially dispersing individual wavelength channels;

f) a focusing element positioned in the path of the confined and realigned orthogonally polarized beams for focusing the beams;

g) a first polarization beam splitter coupled to the focusing element for separating at least one of the first and second output beams that are orthogonally polarized into first and second orthogonal polarization components; and

h) a processing device positioned in the path of the confined and realigned orthogonally polarized beams that includes a series of independent wavelength processing elements for separately processing each of the spatially dispersed individual wavelength channels thereby steering the spatially dispersed individual wavelength channels along predetermined paths such that the first source is configured to switch an optical beam from one of the first plurality of ports to another one of the first plurality of ports and independently the second source is configured to switch an optical beam from one of the second plurality of ports to another one of the second plurality of ports.

2. The dual-source wavelength selective switch of claim 1 wherein the confined and realigned first and second output beam that are orthogonally polarized along the direction of propagation propagate parallel to each other.

3. The dual-source wavelength selective switch of claim 2 wherein the confined and realigned first and second output beam that are orthogonally polarized along the direction of propagation propagate with a predefined spacing.

4. The dual-source wavelength selective switch of claim 1 wherein the first and second sources are positioned parallel to each other.

5. The dual-source wavelength selective switch of claim 1 wherein the first and second sources are positioned at an angle relative to each other.

6. The dual-source wavelength selective switch of claim 1 wherein the processing device comprises an LCOS device.

7. The dual-source wavelength selective switch of claim 1 wherein the collimating element comprises a collimating lens positioned in the path of the confined and realigned orthogonally polarized beams.

8. The dual-source wavelength selective switch of claim 1 wherein the collimating element comprises an optical power element.

9. A wavelength selective switch comprising:

a) one or more input ports for inputting optical beams in a forward direction of propagation;

b) a switching module for reflecting the optical beams propagating in the forward direction and selectively switching the optical beams along predetermined paths in a return direction of propagation;

c) one or more output ports for receiving predetermined optical beams propagating in the return direction; and

d) a port selecting module comprising a beam shifting element configured to shift the optical beams by a predetermined beam displacement, configured to correct an offset of the optical beams, and configured such that unwanted light from the switching module is not coupled to an output port, the port selecting module selectively directing the optical beams such that predetermined ones of the optical beams propagating in the return direction propagate along trajectories out of alignment with the input ports.

10. The wavelength selective switch of claim 9 wherein the beam shifting element is configured such that a wanted light from the switching module is coupled to an output port.

11. The wavelength selective switch of claim 9 wherein the beam shifting element comprises an optical wedge.

12. The wavelength selective switch of claim 9 wherein the beam shifting element comprises a beam compensator.

13. The wavelength selective switch of claim 9 wherein the predetermined beam displacement is substantially 125 μ

m.

14. A wavelength selective switch comprising:

a) one or more input ports for inputting optical beams in a forward direction of propagation;

b) a switching module for reflecting optical beams propagating in the forward direction and selectively switching the optical beams along predetermined paths in a return direction of propagation;

c) one or more output ports for receiving predetermined optical beams propagating in the return direction; and

d) a port selecting module comprising a first and second birefringent wedge wherein a crystalline optic axis of the first birefringent wedge is oriented orthogonal to a crystalline optic axis of the second birefringent wedge, the port selecting module selectively directing the optical beams such that predetermined ones of the optical beams propagating in the return direction propagate along trajectories out of alignment with the input ports and the port selecting module preventing unwanted light from the switching module from coupling to an output port.