Preparation of a novel self-assembling nonlinear optical (NLO) polymer film

A novel self-assembling crosslinking second harmonic generation nonlinear optical (SHG/NLO) film with high SHG coefficient (2×10^-7 e.s.u. by IR dichroism) was prepared by molecular design and “in-situ poling and sol-gel process”. The content of the NLO chromophore (S)-(-)-1-(4)-nitropheny1-2-pyrrolidinemethanol (NPP) is as high as 50 mol% since NPP molecules probably disperse in the film at a molecular level. The film is rigid, uniform and transparent. This designed clathrate supermolecular structure was poved by IR, atomic force microscopy (AFM) and differential scanning calorimetry (DSC) detection. The title film exhibits a long-term temporal stability with 95% of the initial value of SHG coefficient maintained even after 20 d at 65°C (by UV spectroscopy). Project supported by the National Natural Science Foundation of China (No. 59483001)