Acta Phys. -Chim. Sin. ›› 1992, Vol. 8 ›› Issue (02): 156-161.doi: 10.3866/PKU.WHXB19920204

• ARTICLE • Previous Articles     Next Articles

The Dispersions of the Second-Order Nonlinear Susceptibilities of Some Organic Molecules

Feng Ji-Kang; Gao Xu-Ling; Sun Jia-Zhong   

  1. Chemistry Department and Institute of Theoretical Chemistry Jilin University, Changchun 130023
  • Received:1990-08-27 Revised:1991-01-21 Published:1992-04-15
  • Contact: Feng Ji-Kang

Abstract:

At the level of INDO/CI methods, using the program for calculations of the second-order nonlinear susceptibilites (β_(ijk)) written by ourselves, we calculated the β_(ijk) of aniline, nitrobenzene, ρ-nitroaniline and 4-nitro-4′-aminostilbene and inves-tigated dependence of β_(ijk) on LASER frequencies. It is shown that the intramolecular charge transfer is the origin of the nonlinear optics phenomenon and the LASER field plays an important role to the magnitude and direction of the second-order nonlinear optics susceptibility. When the LASER frequency is close to the molecular resonance frequency, the second-order nonlinear susceptibility becomes larger, before and after the resonance freguence, β_(ijk) changes its sign and the Kleinman symmetry begins to break down.

Key words: 4-nitro-4 4aminostilbene; Second-order nonlinear susceptibility; Dispersion