Theoretical investigation electroopticalof nonlinear properties ofchromophores

Organic electrooptical (EO) chromophores are now gaining more attention because the property of organic photorefrative (PR) materials could be controlled by doped EO chromophores. In this paper, nonlinear optical (NLO) properties of a new group of organic electrcoptical chromophores, synthesized recently in our laboratory, were elucidated theoretically with the quantum chemical density functional theory (DFT) and the intermediate neglect of differential overlap Hamilton and the configuration interaction (INDO/CI), as well as semiemperical Austin Modlel 1 (AM1) methods. The electronic transition intensity, dipole moment and the second- order polarizability were obtained. The results show this group of chromophores possess appropriate optical absorption property and good electrooptical property and optical activity. The second-order polarizabilities β are as large as the order of 10^-29 to 10^-28 ESU, indicating the promising applications in the future. The physical mechanism of NLO is discussed by means of molecular orbital and electronic charge distribution.