噻二唑衍生物的三阶非线性光学性能与合成

设计合成了7个新的噻二唑衍生物,用UV、IR1、H NMR和元素分析进行了表征。采用飞秒激光,运用简并四波混频法,研究了衍生物在非共振状态下的三阶非线性光学性能。它们的三阶非线性光学极化率χ(3)为3.75~4.18×10-13esu,非线性折射率n2为6.90~7.68×10-12esu,分子二阶超极化率γ为3.75~4.26×10-31esu,响应时间为101~115 fs。探索了衍生物的分子结构对三阶非线性光学性能的影响。引入离域能小的芳杂环,增长共轭链,形成吸供构型,增大取代基的供电子能力,提高共轭体系的共平面程度等因素有利于获得较大的三阶非线性光学性能。

Third-order optical nonlinearities and synthesis of thiadiazole derivatives

Seven thiadiazole derivatives are synthesized and characterized by UV,IR,1H NMR and elemental analysis.By using femtosecond laser,the off-resonant third-order optical nonlinearities of the derivatives are measured with degenerate four-wave mixing technique.The third-order nonlinear optical susceptibilities χ(3) are 3.75～4.18×10-13 esu.The nonlinear refractive indexes n2 are 6.90～7.68×10-12 esu.The second-order hyperpolarizabilities γ of the molecules are 3.75～4.26×10-31 esu.The response times τ are 101～115 fs.The influence of the molecular structure on the third-order optical nonlinearity is studied.The factors such as introduction of aromatic heterocycle with small delocalization energy,long conjugate chain,formation of acceptor-donor structure,strong electrondonating abilities of substituents,and good coplanarity lead to the high third-order optical nonlinearity.