Abstract

The growing need for spatial light modulators with grey-scale capability and a fast response has stimulated interest in the development of new electroclinic liquid crystals with large tilt angles. The achievable contrast ratio in these devices is limited by the magnitude of the tilt angle as well as by a field-induced deformation of the smectic layers which degrades the extinction. Recently, it was shown that field-induced changes in the birefringence can also contribute significantly to the electrooptic response.¹ In this paper, optical phase retardation measurements are performed to investigate the field dependence of the birefringence and the contrast ratio for a new electroclinic liquid crystal, designated a DSiKN65, which has recently been synthesized and which exhibits both a large electroclinic tilt angle (>22.5°) and a fast response (<100μs).¹ The first observation of a large field-dependent optical biaxiality in this material is reported. The implications on these results on device performance will be discussed.

© 1997 Optical Society of America