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.

Described herein is an optical switch (100), comprising an input array (102) of optical fibers. The array (102) comprises two or more columns of fibers that are spatially offset in one or both of a switching dimension or a dispersive dimension of the optical switch (100). Each column (102A, 102B) of fibers is adapted to project respective optical beams. A switching engine (112) is positioned to receive the optical beams and apply an angular switching to the beams to direct the beams to respective output fibers. The optical beams are encoded at respective angles or polarization states such that each column of optical beams is incident onto a different region of the switching engine (112).

A coherent multi-beam optical phased array for radio-frequency beamforming is provided. The optical phase array includes an optical signal source generating an optical signal, a first set of waveguides connected to the optical signal source and configured to propagate the optical signal, a second set of waveguides, a set of splitters along each of the first set of waveguides configured to split the optical signal, a phase shifter coupled to each of the splitters, each phase shifter being controllable to modify a phase shift of the optical signal, a coupler connected to each of the phase shifters and to one waveguide of the second set of waveguides for introducing the optical signal after shifting, and a photodetector coupled to each waveguide of the second set of waveguides and configured to receive a heterodyne optical signal from the waveguide and generate a corresponding electrical signal.