Polymer-dispersed chiral smectic A with photorefractive properties

We present results on the photorefractive properties of chiral smectic A li quid-crystal phases dispersed in cylindrical cavities in a photoconducting polymer. The refractive-index modulation is due to the electroclinic effect , which is linear in the electric field, in contrast with the effect that i s due to the dielectric anisotropy that is typical of nematic phases. We ob tained grating buildup times of similar to 25 ms, limited by the speed of t he space-charge field formation in the photoconducting matrix. (C) 2001 Opt ical Society of America.