Scattering of Coherent Light from Nematic Liquid Crystals in the Dynamic Scattering Mode

Measurements of the scattering of laser light by anisylidene‐para‐amino‐phenylacetate (APAPA) in the ``dynamic scattering'' mode associated with the passage of electric current have been made. The results have been interpreted by means of a model in which the light scattering is due to amplitude and phase modulation resulting from orientation fluctuations induced by the current flow. Coherence distances for the liquid crystal film are derived which are expected to give an inverse measure of the turbulence in it. The coherence distances are found to depend very strongly on the polarization of both incident and scattered light and to decrease markedly with either increased applied voltage or increased thickness; these results are explained in terms of the theoretical model.