Second hyperpolarizability measurements of organic materials by third harmonic hyper-Rayleigh scattering

This study contributes to search for efficient nonlinear optical (NLO) materials for photonic integrated chips, where silicon's limited activity necessitates alternatives. Organic materials are promising due to their high molecular polarizability and structural versatility. Typically to characterize organic NLO materials While Hyper-Rayleigh scattering (HRS) typically is used to evaluates first molecular hyperpolarizability(β). In this study utilizes third harmonic scattering (THS) to determine second hyperpolarizability (γ) in novel organic compounds. Using a tunable femtosecond laser (1200– 1600 nm), concentration-dependent THS measurements were performed using internal and external (CS2) references. Results were validated against Z-scan measurements, providing a comparative analysis of these methodologies for characterizing intrinsic third-order NLO efficiencies.