Patent ID: 6028656
Filing Date: 2000-02-22
Classification: G02F

Abstract:
An optical polarization switch acting upon incident light having a polarization state along a polarization axis, comprisinga first nematic liquid crystal cell which selectively alters polarization of light passing therethrough depending upon an application of external energy to said first nematic liquid crystal cell, but which does not substantially displace the path of the light;a second nematic liquid crystal cell which selectively alters polarization of light passing therethrough depending upon an application of external energy to said second nematic liquid crystal cell but which does not substantially displace the path of the light, said second nematic liquid crystal cell being arranged in optical series with said first nematic liquid crystal cell;a compensation means interposed between said first and second nematic liquid crystal cells, wherein said compensation means comprises one of an optical rotator effecting substantially 90.degree. rotation of the polarization state of light exiting the first nematic liquid crystal cell, an optical half-wave retarder having a slow axis oriented substantially parallel to the polarization axis of the incident light, and an optical half-wave retarder having a fast axis oriented substantially parallel to the polarization axis of the incident light.