Nonlinear optical properties of metal-alkanoate liquid crystalline media

Abstract

This work presents the analysis of experimental data on studies of optical and nonlinear optical properties of lyotropic ionic liquid crystals of potassium caprylate doped with electrochromic viologen admixtures, and smectic glasses of thermotropic ionic liquid crystals of cobalt alkanoates homologous series (number of carbon atoms in alkanoate chain n = 7, 9, 11) and their multicomponent mixtures. Prior to performing nonlinear optical experiment the optical absorption spectra for all samples were investigated. Laser induced dynamic grating recording under the action of nanosecond laser pulses was realized, observed and analyzed for the proposed absorptive media. It was discovered that studied materials are characterized by cubic optical nonlinearity and have values of cubic nonlinear susceptibility χ(3) and hyperpolarizability γ comparable with the best characteristics of organic dyes. The possible mechanism of nonlinear response in studied systems was considered on the base of obtained data. The nonlinear response mechanism is connected with nonlinear polarization of π-electrons in the field of laser radiation.