摘要
The relaxation of optically excited carrier in C_(70) thin film fabricated by physical jet deposition was investigated by femtosecond pump-probe measurements.A transient decrease in transmission was observed indicating induced absorption.In comparison to C_(60) thin film the initial response of C_(70) film is laser pulse limited and the long lived component has smaller magnitude.The third order optical nonlinear susceptibility of C_(70) thin film was determined to be χ^((3))=3.3×10^(-11) esu by femtosecond time-resolved optical Kerr effect.From the primarily pulse limited response the dephasing time of C_(70) thin film has been proved to be shorter than the laser pulse width.
基金
Supported by the National Natural Science Foundation of China。
