Abstract

Liquid crystal spatial light modulators (LC SLMs)¹ have important uses in optical processing, such as wavelength conversion, wavefront correction, and optical computing. LCs with high birefringence and low viscosity are highly desirable for enhancing the figure of merit of the LS SLM. In this paper, a three-band model which consists of one σ → σ^* and two major π → π^* electronic transitions was developed to account for the birefringence dispersion of a uniaxial liquid crystal. By comparing theory with experimental results, the contribution of each band to the overall birefringence is evaluated quantitatively. The effect of each band on birefringence dispersion depends strongly on the conjugation length of the LC molecule. By increasing the conjugation length along the principal molecular axis, the longest π → π^* transition plays an ever-increasingly important role in birefringence, whereas the contributions from the σ → σ^* and the first π → π^* transitions decrease.

© 1989 Optical Society of America