Third-order nonlinear optical properties of two novel fullerene derivatives

The third-order nonlinear optical properties of two novel fullerene derivatives under picosecond laser excitation have been investigated by the Z-scan technique. The experimental results reveal that all the derivatives have nonlinear absorption coefficient under excitation of 532 nm pulses and a high third-order nonlinear refraction index under excitation of 1064 nm pulses. The molecular second hyperpolarizabilities have been obtained from our experimental results.