Investigation of third-order nonlinear optical properties of two azo-nickel chelate compounds

摘要

This paper investigates the third-order nonlinear optical properties of two azo-nickel chelate compounds by the optical Kerr gate method at 830 nm wavelength with pulse duration of 120 fs. Both of the two compounds exhibited large third-order optical nonlinearity. The second-order hyperpolarizability,γ,of Compound 1 is of 1.0 × 10 31 esu. Due to the charge transfer,the γ of Compound 2 with electron donor and acceptor group is 4.9 × 10 31 esu,which is a four-time enhancement in comparison with Compound 1. The absorption spectra show that the electron push-pull effect,which induces intramolecular charge transfer,leads to the increased optical nonlinearity.