不同表压下芪盐LB膜二阶光学非线性的研究

研究了芪盐在不同表压下制备的ＬＢ膜的二阶光学非线性。测量得到在低表压增强的二次谐波信号。对比芪盐的π－Ａ曲线和透射光谱，认为在ＬＢ膜中芪盐以固相态存在，低表压时的固相态聚集体的吸收峰３５１ｎｍ使四阶非线性极化率Ｘ＾（４）（－２ω：ω，ω，ω，－ω）产生共振强，四阶光学非线性现象对二次谐波信号产生影响。

Study of Second-Order Nonlinear Optics for Stilbazium Salt Langmuir-Blodgett Monolayer at Different Surface Pressure

Second- harmonic generation (SHG ) of stilbazium salt Langmir-Blodgett monolayer at different surface pressure was measured. We got the enhanced SHG signal at low surface pressure. Refering to surface pressure-area isotherm and the transparent spectra of stilbszium salt we got following results. The stilbazium salt on LB film was in the form of solid state. The absorption peak 351 nm of the solid aggregation at the low surface pressure led to resonant-enhancement of the fourth order nonlinear optical susecptibility Ｘ(4)(—2ω:ω,ω,ω,—ω) which gives an effecton to SHG signal.