STUDIES OF 3RD-ORDER OPTICAL NONLINEARITIES IN C-60-TOLUENE AND C-70-TOLUENE SOLUTIONS

Third-order optical nonlinearities in C60- and C70-toluene solutions were studied by using a time-delayed degenerate four-wave-mixing technique with 30-ps pulses at 0.532-mu-m in both parallel- and cross-polarization configurations. The concentration dependences of chi-1212(3) were measured for C60-and C70-toluene solutions. In order to explain the strange concentration dependence of chi-1212(3) in the C70-toluene solution, the sign of the contribution from the C70 molecules was assumed to be opposite the sign of that from toluene.