Polarization independent light switching device based on liquid crystals

Abstract

A light guiding element for routing a light signal between an input port and an output port or for blocking the propagation of the light signal between the input and output ports depending on the state of the switching element. The guiding element utilizes a beam splitter for separating the input light signal into physically separated first and second polarized light signals, the first light signal having a polarization that is orthogonal to that of the second light signal. A first polarization rotator rotates the polarization of the first light signal such that the polarization of the first light signal is parallel to that of the second light signal. A first waveguide having first and second states operates on the first light signal such that the first waveguide guides the first light signal along a predetermined path in the first state while not guiding the first light signal in the second state. A second waveguide having first and second states operates on the second light signal such that the second waveguide guides the second light signal along a predetermined path in the first state while not guiding the second light in the second state. A second polarization rotator rotates the polarization of the second light signal such that the polarization of the second light signal is orthogonal to that of the first light signal. A beam combiner then combines the first and second light signals and couples the same to the output light port.

Dependencies are inferred from the claim text.