Transient light scattering of ferroelectric liquid crystals enhanced by adding ferroelectric liquid crystalline polymers

A side-chain type ferroelectric liquid crystalline polymer (FLCP) was mixed with a low-molecular-weight ferroelectric liquid crystal (LMWFLC) to improve the light switching contrast for the transient light-scattering mode (TSM). Optical transmittance through an optically homogeneous chiral smectic C phase in a FLCP/LMWFLC composite system was observed by a polarizing optical microscope. The transmittance of the transparent state of the composite system upon the application of an a.c. electric field was almost the same in comparison with that of LMWFLC. On the other hand, the light-scattering intensity for the composite system upon the application of an a.c. electric field was somewhat stronger than that for LMWFLC. The enhancing mechanism of the transient light scattering induced by an addition of FLCP to LMWFLC has been discussed through the light switching measurements for free-standing FLC thin films.