Hexagonal Inorganic Metal Cluster Compound [the W <sub> 2 </ Sub> Ag <sub> 4 </ Sub> S <sub> 8 </ Sub> (pph <sub> 3 </ Sub>) <sub> 4 </ Sub>], The Optical Nonlinearity

In this dissertation, the recent results, and analysis methods, and theories of optical nonlinearities of metal clusters were summarized systemically. A kind ofsensitive measurment of optical nonlinearities using a single beam--Z-scantechnique and its theoretical analysis were reviewed in detail and compared with others measurement method. The characteristic and applications of these techniques were analyzed. The nano-second optical limiting models of reverse saturable absorption under the steady-state approximation was established.A hexagonal prism cage shaped inorganic metallic cluster compound [W2Ag4S8(PPh3)4] solution in CH2Cl2 was investigated based on the Z-scan technique using a single beam. It shows strong nonlinear absorption and self-focusing performance. Its three-order nonlinear refraction index and nonlinear absorption cofficient and three-order polarization cofficient were calculated.We also studied the optical limiting properties of the metal cluster solution in DMF with the wavelength of 532nm, pulse duration of 8ns, repetition frequency of 1 Hz laser pulses. The optical limiting mechanism is attributed to nonlinear absorption and nonlinear scattering.