Three-coupled-oscillator model for nonlinear optical response of chiral molecules with tripod-like structure

In this paper, we further study on the relation between the first hyperpolarizability and molecular configuration based on the three-coupled-oscillator model proposed by us. The model is suitable for chiral molecules with the tripod-like structure. We numerically simulate the spectra of first hyperpolarizabilities, and investigate the effects of molecular chiral parameters and coupling coefficients on the hyperpolarizabilities. As an example, we show a calculation of the first-hyperpolarizability spectra for NPAN molecules, which accord well with the experimental result obtained by Barzoukas et al. [M. Barzoukas, D. Josse, P. Fremaux, J. Zyss, J. Opt. Soc. Am. B 4 (1987) 977-986].