Angular-scattering characteristics of ferroelectric liquid-crystal electro-optical devices operating in the transient-scattering and the extended-scattering modes

The angular distribution of forward-scattered light in transient-scattering -mode (TSM) and extended-scattering-mode (ESM) ferroelectric liquid-crystal (FLC) devices was evaluated by use of circularly polarized incident light. For both modes the intensity and the distribution of forward-scattered lig ht depended primarily on the FLC birefringence, spontaneous polarization, a nd the cell path length. In the FLC materials examined, the forward-scatter ing intensity under ESM drive conditions increased with longer FLC pitch le ngths, whereas under TSM conditions stronger forward scattering was observe d with increasing FLC spontaneous polarization. Although both TSM and ESM d rive conditions displayed a similar angular distribution for forward-scatte red light, the intensity of ESM scattering over a 0 degrees-6 degrees range was considerably smaller than that observed in earlier experiments with li nearly polarized incident light. (C) 1999 Optical Society of America. OCIS codes: 160.2260, 160.2100, 160.3710, 290.5820, 260.3060, 230.3720, 230.4110 , 040.3060.