RAYLEIGH-SCATTERING FROM COLUMN UNDULATIONS IN A DISCOTIC LIQUID-CRYSTAL

Depolarized Rayleigh scattering on a columnar discotic liquid crystal is described. Column undulations and mode quantization allow the scattering to,be visible only for two directions of reciprocal space, and for well-defined light propagation angles. The observed constant angular extension of the scattering shows that column undulations are not controlled by curvature elasticity, but by an anisotropic 3D solid-like elasticity. This behavior is probably associated with column entanglement, as recently discussed by Prost.