Kerr coefficient and third-order nonlinear optical absorption coefficient of isotropic diacrylate mesogens at 632.8 nm wavelength

Abstract

ABSTRACT Third-order optical nonlinearities of diacrylate mesogens RM82 and RM257 in the isotropic phase for a low-power continuous wave laser irradiation at 632.8 nm wavelength have been studied. In their isotropic state, the diacrylate mesogens exhibit quite large nonlinear absorption. We observe a large two-photon absorption coefficients, on an order of 10−6 m/W, for the mesogens. The Kerr coefficients of the mesogens are characterised using single beam Z-scan technique, and found to reach an order of 10−7 m/W. Both diacrylate mesogens exhibit a good material figure of merit.