Observation of light-induced hydrodynamic instabilities in a nematic liquid crystal for a single-mode laser beam

A new mechanism of optical switching in dye doped nematics due to the excitation of hydrodynamical instabilities with a light controlled topology is presented for the first time. The optical bistability and self-diffraction effects due to intrinsic multiplicative feedback are observed as well. A single-mode cw laser beam was used in the experiment as a pump radiation.