Off-resonant nonlinear optical properties of C 60 studied by degenerate four-wave mixing

Abstract

Pure C 60 was deposited on optical substrates in vacuo and spectroscopically characterized. A small linear absorption coefficient α=6 cm −1 was measured at 1.064 μm. Time-resolved degenerate four-wave mixing experiments were conducted on films of pure C 60 using a 35 ps Nd: YAG laser at 1.064 μm. The third-order optical susceptibility x xxxx (3) of C 60, derived from its phase conjugate signal, is 7×10 −12 esu. The nonlinear optical temporal response was largely laser-pulse limited. Evidence for a fifth-order contribution to the nonlinear optical response was observed at high laser intensities.