Nonresonant third-order optical nonlinearity of all-carbon molecules C60

The nonresonant third-order hyperpolarizability of all-carbon molecules C60 is measured by nanosecond degenerate four-wave-mixing experiment in C60 toluene solution. The value of γ1111 measured is 1.6×10−31 esu, which corresponds to an estimated value of the third-order nonlinear optical susceptibility χ(3)1111E = 3.3 × 10−9 esu for the solid compound.