| The electro optical response of liquid crystalline materials while displaying anisotropic properties, has led to numerous optical applications.;A retro-reflecting modulator for optical communication systems using a high numerical aperture objective lens and a planar aligned nematic liquid crystal electrooptic cell that tunes the optical path length in the liquid crystal layer as a function of applied voltage has been developed. The field-induced phase shift varies the dependence of liquid crystal layer reflectivity in angle of incidence. This dependence can be studied in-situ by performing positional scan, z, along the axis of symmetry of the lens scan, focusing the light with an aberrative lens such that angle of incidence depends on z and measuring the reflectivity in the far field. These data show that a low reflected state can be achieved when liquid crystal thickness such that destructive interference with paraxial angle of incidence and high field "hometropic" orientation. |
