High contrast switching of transmission due to electrohydrodynamic effect in stacked thin systems of liquid crystals.

We study the opportunity of using electrohydrodynamic instabilities in a nematic liquid crystal mixture with negative dielectric anisotropy for controlling laser beams. Switching between naturally transparent and diffuse light scattering states is achieved by application of low frequency, low amplitude voltages. The specifics of diffuse light scattering state depending on the orientation and thickness of the liquid crystal layer are revealed. The switching occurs on a milliseconds time scale. Combination of thin, flexible liquid crystal cells allows polarization independent, high contrast, fast switching in a broad band of visible wavelengths.