Large Non-resonant Nonlinear Optical Susceptibility of Cu₂O Microcrystallites

We report the measured results of non-resonant nonlinearity by degenerate four-wave mixing for Cu₂O nanoparticles having central diameter of 9nm. The value of (3) obtained in a 10ns pulse experiment is 8.48 x 10^-10 esu, and the nonlinear response time of the sample is estimated to be in the order of nanosecond.