利用1.064 μm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光聚合后二阶非线性的提高可以用电四极子和磁偶极子对二次谐波贡献的增强来解释。

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.