Picosecond third-order nonlinear optical susceptibility in nematic liquid crystals

Abstract
We have measured the tensor components c 1111 and c 1221 of third‐order nonlinear optical susceptibility of two nematic liquid crystals, MBBA (p‐methoxy‐benzylidene p‐n‐butylaniline) and EBBA (p‐ethoxy‐benzylidene p‐n‐butylaniline), in the picosecond regime. We observed that the molecule with ethoxy group (EBBA) has a larger third‐order nonlinearity than the one with methoxy group (MBBA) and present a model to explain this effect.