Theoretical and experimental comparative study of nonlinear properties of imidazolium cation based ionic liquids

Abstract This work describes the experimental and theoretical investigation of the nonlinear optical properties of the imidazolium cation based ionic liquids and the corresponding thermo-optical parameters. The experimental results of nonlinear optical properties, such as nonlinear refractive index and thermo-optical properties are determined by Z-scan and EZ-scan techniques with a femtosecond laser source. Theoretical simulations of linear and nonlinear optical properties performed by density functional theory (DFT) are discussed in terms of polarizabilities and hyperpolarizabilities. A correlation between the theoretical and experimental results is presented, where the variation of the experimental signals of each ionic liquid can be compared with their calculated nonlinear optical properties.