本文提出了一种利用二噻吩乙烯来设计光致二阶非线性光学开关分子的新方案.与传统设计方案不同之处在于,新方案中,二噻吩乙烯主要作为一个得失电子能力可以改变的基团处于化合物的端基上.通过设计一组结构简单的模型化合物,并利用密度泛函理论计算它们的一阶超极化率β,我们实验了新方案的效果.计算结果表明,使用适当的取代基,能使设计的分子的光异构体之间的β比值达到10倍左右,差值超过100×10-30esu,使得这组模型化合物的二阶非线性光学开关能力不逊色于一些遵循传统设计方案的复杂金属有机化合物. In this paper, we propose a novel scheme for designing photoinduced second-order nonlinear optical switch molecules using dithienylethylene.Compared with the traditional design scheme, the dithienylethylene mainly acts as a basis for gain and loss of electron capacity Group is located at the end of the compound.We have tested the effect of the new scheme by designing a set of simple model compounds and using the density functional theory to calculate their first-order hyperpolarizabilities β.The results show that using the appropriate Substituent, can make the molecular design of the β-ratio between the photo-isomers of about 10 times, the difference of more than 100 × 10-30esu, making this group of model compounds of second-order nonlinear optical switching capability is not inferior to some follow Traditional design scheme of complex metal organic compounds.