Synthesis and characterization of polyphosphazene with double electro-optic molecules thin film and its application

摘要

Polyphosphazene with double electro-optic (EO) molecules was synthesized. One kind of the chromo-phoric group (carbazole nitro-azobenzene) was grafted to the polymer main chain by a chemical method to form the side chain EO polymer (carbazole polyphosphazene grafted with 2,4-dinitroaniline). Then, another small nonlinear optical molecule (NLO), ethyl 4-(dimethylamino) benzoate (EDB), was mixed into the polymers by a physical method for further improvement of EO properties. The structure of the material was characterized and the effect on the EO coefficient of different mixing proportions was investigated. Experimental results show that the material has fine stability and its enhanced EO coefficient is 40.5 pm/V. Thin films formed by this polymer material were used to detect terahertz (THz) radiation. It is found that the detecting efficiency and the spectrum sensitivity are enhanced largely compared with inorganic crystals, which makes the polymer material a good candidate for THz application.