超高真空中C60光聚合效应光学二次谐波的研究

利用１．０６４μｍ基频超短脉冲激光，使用光学二次谐波方法研究了超高真空中蒸镀在多晶银表面上的Ｃ６０薄膜紫外光照射下的光聚合现象，发现聚合以后的Ｃ６０二阶非线性响应增强，同时观察到光聚合的饱和效应，Ｃ６０光聚合二阶非线性的提高可以用电四极了磁偶极子对二次谐波贡献的增强来解释。

Photopolymerization of C 60 Films in Ultrahigh Vacuum Observed by Second Harmonic Generation

Using 1.064 μm wavelength laser pulses, the photopolymerization of C 60 films on a polycrystalline Ag surface under ultrahigh vacuum (UHV) environment is investigated by optical second harmonic generation (SHG) method. It is found that the intensity of the SHG signals from C 60 films increases with the extension of exposure time under ultraviolet light, and finally reaches to a saturation value. We suggested that the enhanced second harmonic generation from photochemically modified C 60 films is induced by the reinforce of bulk electric quadrupole polarization and magnetic dipole.