一种新型材料的LB膜及非线性光学特性研究

Langmuir-Blodgett Film and Second-Order Nonlinear Optical Properties of a Novel Material

研究了一种包含西佛氏碱和萘酰亚胺的新型材料的LB膜的制备 ,并采用π A等温曲线和紫外 可见吸收谱对其LB膜的制备特性进行了表征。单分子膜的崩溃压力在 30mN/m左右 ,对应的单分子的面积约为 1.8nm2 。π A等温线的固相区较为陡峭 ,在空气 水界面上 ,能形成了较好的单分子膜 ,并可以较好的转移到固体基板上 ,转移比可保持在 1± 0 .1的范围内。采用二次谐波产生的方法研究了LB单层膜的二阶非线性光特性。测量了二次谐波强度随基频光入射角的变化关系 ,其二次谐波信号的最大值在约 6 0°的入射角处。这种化合物具有较大的二阶非线性极化率。它的二阶非线性光特性起源于由苯乙烯形成的共轭π

Langmuir-Blodgett Film of a novel material which contain Schiff-base and naphthalimide has been made and characterized by using the surface pressure-area (π-A) isotherm line and UV-visible absorption spectra. The breakdown pressure of the monolayer was about 30 mN/m. The area occupied by each molecular was about 1.8 nm 2. The π-A isotherm line shown a steep solid field which demonstrated that this molecules could form a good monolayer on the water surface. The UV-visible absorption spectra shown that the molecule could be deposited onto solid substrate. The transfer ratio was kept in the range 1±0.1. The second-order nonlinear optical properties have been investigated by using second harmonic generation (SHG) technique in Langmuir-Blogett monolayer. The dependence of SHG intensity on the incident angle of fundamental is measured beam. A maximum in SHG intensity was obtained at the incident angle of 60°. The second order nonlinear optical susceptibility χ (2) is about 1.51×10 -9 esu. The origin of second harmonic generation is attributed to the conjugation system formed by phenylenevinylene.