FEMTOSECOND OPTICAL KERR STUDY OF HEAVY-ATOM EFFECTS ON THE 3RD-ORDEROPTICAL NONLINEARITY OF THIOPHENE HOMOLOGS - 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 hy perpolarizabilities were found to increase with increasing atomic numb er of the heteroatom of the homologues at each incident wavelength. Al so the dispersion of the hyperpolarizabilities was found to be insigni ficant. Heavy atom effects on the hyperpolarizabilities are discussed in terms of the perturbation expansion expression.