Theoretical studies on third-order nonlinear optical property

Abstract

The third-order nonlinear optical ( NLO) properties of ( ZnS) (6-12) were investigated under the time dependent density functional theory(TDDFT) at B3LYP/ Lanl2lZ +6-31G(center dot) level. The static third-order susceptibilities chi((3)) and dynamic behavior of third-order polarizabilities gamma in 0 - 2.5 eV were calculated by using the sum over states( SOS) method. The results show that the X (3) of ( ZnS) 6-12 clusters are better than that of the other semiconducting clusters. (ZnS)(7) and (ZnS)(11), respectively, had a remarkable gamma value of -2.38 x 10(-33) and 1.26 X 10(-13) esu at 1.6 and 2. 0 eV. The ( ZnS)(6-12) clusters can produce an obvious phenomenon of the third-order polarizabilities when they are excited in a large gamma value area.