  We study light transmission through a homeotropically oriented nematic liquid
crystal cell and solve self-consistently a nonlinear equation for the nematic
director coupled to Maxwell's equations. We demonstrate that above a certain
threshold of the input light intensity, the liquid-crystal cell changes
abruptly its optical properties due to the light-induced Freedericksz
transition, demonstrating multistable hysteresis-like dependencies in the
transmission. We suggest that these properties can be employed for tunable
all-optical switching photonic devices based on liquid crystals.
