Liquid crystal optical switch

Abstract

The present invention, which relates to a polarization control liquid crystal optical switch for optical communication and its drive method, may be applied to the wavelength division multiplexing (WDM) communication method and an optical network using optical fibers. The liquid crystal optical switch comprises a liquid crystal polarizing rotator including at least one polarization control liquid crystal cell, wherein, at polarization rotation operation time, the liquid crystal polarizing rotator acts as a half-wave plate for linearly polarized light with a predetermined wavelength which enters the liquid crystal polarizing rotator. The polarization control liquid crystal cell has a function that varies a center wavelength to be used when the polarization control liquid crystal cell acts as the half-wave plate, and a function that maximizes a cross-talk attenuation.

Dependencies are inferred from the claim text.