Third-order nonlinear optical interactions of C60 and C70

Abstract
We measured the third‐order nonlinear optical susceptibility χ(3) for C60 and C70 solutions as a function of concentration using degenerate four‐wave mixing with picosecond pulses at 532 nm. From the observed minimum we were able to obtain the real and imaginary parts of χ(3). The real part is negative at this wavelength. Values of the real and imaginary components of the molecular hyperpolarizability (γ) calculated are in the range 10−31 esu.