利用表面等离子激元波技术来测定极薄膜层的光学参量是相当灵敏的,但拟合计算结果往往会得到两组不确定的解。本文报道一种采用Otto耦合结构、通过测量相对于空气隙厚度变化取最小的反射率来唯一确定介质膜层复介电常数和厚度的方法。文章最后给出3对具有不同分子层数的Langmuir-Blodgett膜的测试结果。

The surface-plasma-wave technique is a very sensitive way used for determining the optical constants of ultra-thin films. In this paper we propose a new method to determine the dieleotrical coefficient and thickness of Langmuir-Blodgete film unambiguously by measuring the angle spectrum of minimum reflectivity with respect to thickness of air gap in Otto's coupling system. Experimental results for arachidic acid LB films with different number of molecular layers are presented.