Observation of light-induced hydrodynamic instabilities in a nematic liquid crystal in a single-mode laser beam
Galstyan T. V., Drnoyan V. E., Alaverdyan R. B., Arakelyan S. M., Chilingaryan Yu. S.
Light-induced hydrodynamic instabilities have been discovered and studied in a nematic liquid crystal which is initially in a state of uniform orientation. The instabilities occur when a single-mode laser beam excites convective flows and dynamic orientation structures with a complex (and controllable) topology. These structures lead to a self-induced diffraction and to a scattering of light with an optical bistability. These effects stem exclusively from a multiple internal feedback which arises in a strongly absorbing nematic liquid crystal. These effects are observed in an all-optical experiment, without any additional quasistatic fields or initial temperature gradients.