Femtosecond optical Kerr study of heavy-atom effects on the third-order optical non-linearity of thiophene homologues: electronic hyperpolarizability of tellurophene

摘要

Second hyperpolarizability #gamma# of tellurophene (C_4H_4Te), a tellurium-containing homologue of thiophene, was measured by optically heterodyne-detected optical Kerr effect (OHD-OKE) experiments. We found that the #gamma# of tellurophene was +6.3 * 10~(-36) esu and was larger than twice of that for selenophene and almost three times that for thiophene. The large #gamma# for tellurophene as the homologue was discussed in terms of the symmetry species of the two lowest excited states and their transition energies from the ground state under the 3-state approximation. Low-lying excited A_1 state is presented as the plausible cause of the large #gamma#.