Abstract: In a wavelength selective switch, an input port transmits an input beam, and diffraction grating disperses the input beam into optical channels. A liquid-crystal-on-silicon (LCoS) switch assembly has a phase grating profile and has addressable pixels, which are liquid crystal based. The LCoS switch assembly can selectively direct first-order diffracted beams of the optical channels for output to selected output ports. A tunable optical wedge adjacent the LCoS switch assembly can direct higher-order diffraction beams in the space between the output ports to reduce crosstalk. The wedge is a liquid crystal cell having spaced-apart resistive layers and having liquid crystal material disposed between the layers. In the wedge, the liquid crystal material can produce a phase profile in response to bias voltages applied to the resistive layers, and a beam steering angle of the phase profile can direct at least the second-order diffracted beams towards the port spacing between the ports.

Abstract: A multiple wavelength selective switch has an optics assembly to receive a first input optical signal from a first ingress port and a second input optical signal from a second ingress port. A switch assembly has a single switching mechanism to direct the first input optical signal to the optics assembly as a first output optical signal and the second input optical signal to the optics assembly as a second output optical signal. The switch assembly directs the first output optical signal to a first egress port selected from the first set of egress ports and directs the second output optical signal to a second egress port selected from the second set egress ports. The first egress port and the second egress port have the same wavelength channel. The multiple wavelength selective switch supports an arbitrary number of wavelength channels that can be switched at the same time. Each switch assembly directs signals from a set of ingress ports to a set of egress ports sharing the same wavelength channel.