Femtosecond optical Kerr study of heavy atom effects on the third-order optical nonlinearity of thiophene homologues: purely electronic contribution

By using the femtosecond optical heterodyne detected optical Kerr gate technique and Fourier transform analysis, the purely electronic third-order hyperpolarizabilities were determined for furan, thiophene and selenophene at incident wavelengths of 750 and 790 nm. The observed hyperpolarizabilities were found to increase with increasing atomic number of the heteroatom of the homologues at each incident wavelength. Also the dispersion of the hyperpolarizabilities was found to be insignificant. Heavy atom effects on the hyperpolarizabilities are discussed in terms of the perturbation expansion expression.