文摘
The nonlinear absorptive property of a novel metal cluster [WS4Cu3I(4-bpy)3]n in DMF solution is studied byusing an open-aperture Z-scan technique with picosecond and nanosecond laser pulses at the wavelength of532 nm. The experimental results show that the cluster has strong nonlinear absorption under the 8 ns pulseexcitation and a relatively weak nonlinear absorptive property under the picosecond pulse excitation. Thepicosecond pump-probe response of the metal cluster is similar to that of C60 solution, which implies thatthe nonlinear mechanisms are the same for the two materials. By using the rate-equation model, the experimentaldata are theoretically simulated; several optical parameters of the cluster, especially the lifetime of the higherexcited singlet state of the cluster, are obtained.