Investigating the effects of intermolecular interactions on nonlinear optical properties of binary mixtures with high repetition rate femtosecond laser pulses

Measurements of nonlinear optical (NLO) properties of different binary mixtures having carbon disulfide (CS 2 ) as the common component, namely CS 2 -acetone, CS 2 -cyclopentanone, CS 2 -toluene, and CS 2 -carbon tetrachloride (CCl 4 ), are carried out by using the z-scan technique. Open-aperture z-scan (OAZS) and close-aperture z-scan (CAZS) experiments are performed to determine the nonlinear absorption coefficient (β) and nonlinear refractive index (n 2 ) of all binary liquid mixtures at various compositions of the components by employing a pulsed, high repetition rate (HRR) femtosecond laser. Also, we were able to use the flowing liquid to measure NLO properties in the CS 2 -acetone binary mixture to remove the cumulative thermal effects produced due to the pulsed HRR laser light. Nonlinear refractive index (n 2 ) values are found to be influenced by the weak dipole-induced dipole intermolecular interactions between the nonpolar CS 2 and polar acetone as well as cyclopentanone of the respective binary mixtures. On the contrary n 2 values are not found to be affected by the intermolecular interactions in CS 2 -toluene and CS 2 -CCl 4 binary mixtures. In comparison, the nonlinear absorption coefficient (β) values are not found to be affected by the same in all different sets of binary mixtures.