Measurements of the Orientational Elastic Constants of the Nematic Liquid Crystal by A Four-Wave Mixing

Abstract

The diffraction efficiency of an optically induced diffraction grating was measured in a homogeneously aligned cell of a commercial nematic mixture ZLI1738. Both self-diffraction of the pump beams and the diffraction of a probe beam were studied. The diffraction efficiency was calculated analytically with some reasonable approximations. In the calculation the finite beam sizes were taken into account. From the experimental data bend and splay orientational elastic constants were calculated.