title: Molecular structure-property correlations from optical nonlinearity and thermal-relaxation dynamics.
abstract: We apply ultrafast single beam Z-scan technique to measure saturation absorption coefficients and nonlinear-refraction coefficients of primary alcohols at 1560 nm. The nonlinear effects result from vibronic transitions and cubic nonlinear-refraction. To measure the pure total third-order nonlinear susceptibility, we removed thermal effects with a frequency optimized optical-chopper. Our measurements of thermal-relaxation dynamics of alcohols, from 1560 nm thermal lens pump and 780 nm probe experiments revealed faster and slower thermal-relaxation timescales, respectively, from conduction and convection. The faster timescale accurately predicts thermal-diffusivity, which decreases linearly with alcohol chain-lengths since thermal-relaxation is slower in heavier molecules. The relation between thermal-diffusivity and alcohol chain-length confirms structure-property relationship.
authors: Department of Chemistry, Indian Institute of Technology, Kanpur 208 016, India.
authors: Indrajit
authors: I
authors: Bhattacharyya
authors: Shekhar
authors: S
authors: Priyadarshi
authors: Debabrata
authors: D
authors: Goswami