Abstract

The problems of light-induced pitch dilation of the cholesteric liquid crystal (CLC) helix under the conditions of selective Bragg reflection of circular polarized light with changing of reflectivity of the CLC have been widely discussed theoretically, e.g. refs. 1,2. Two mechanisms have been considered: (1) action of strong electric and. magnetic field of intense light wave,^1,2 and (2) heating of the CLC by photo-absorption.² In experiments, only thermal changes of selective reflection band have been observed in absorbing CLCs, e.g. refs. 3-5. On the contrary, in pure CLCs the authors of⁶ using short pulses (15 ns) were unable to detect any changes of reflectivity predicted in ref. 1. There is the only set of papers, e.g. ref. 7, where the changes of curvature of CLC mirrors were explained by pitch dilation in the field of light wave.

© 1996 Optical Society of America