SUBPICOSECOND STUDIES OF THE 3RD-ORDER OPTICAL NONLINEARITIES OF C-60-TOLUENE SOLUTIONS

The third-order optical nonlinearities of C-60-toluene solutions are s tudied employing transient degenerate four-wave mixing (DFWM) and z-sc an techniques using 0.5 ps laser pulses at 497 nm. The concentration d ependence of the chi((3)) of the solution and both the sign and the ma gnitude of the real and imaginary parts of the third-order susceptibil ity of C-60 are obtained. The molecular second hyperpolarizability gam ma of C-60 is found to be (2.3 +/- 0.6) x 10(-32) esu. The role of non linear absorption and its influence on the DFWM signal is discussed. F inally a comparison of our experimental data with other data in the li terature is given.