椭偏光法研究晶体各向异性光学性质——对KNSBN铁电晶体的应用

MEASUREMENT OF ANISOTROPIC OPTICAL CONSTANTS BY ELLIPSOMETRY APPL ICATION ON KNSBM FERROELECTRIC CRYSIALS

本文分析了椭偏光法测量各向异性晶体时入射角和起偏角对测量灵敏度的影响,着重讨论了如何选择合适的实验条件以测量低度各向异性(|n_o—n_e|<0.1)晶体的光学性质。利用单波长椭偏仪和多波长椭偏谱仪测量了方解石和KNSBN铁电晶体样品,得到各向异性折射率和消光系数值,与文献有关结果作了比较。对于|n_o—n_e|<0.1的KNSBN铁电晶体,获得了可靠的结果。

The effects of the incidence angle and the azimuth of polarizer on the sensitivity, in the ellipsometric measurement of anisotropic crystal have been analyzed. We discuss how to choose the proper experimental condition to measure the optical contants of crystal with small anisotropic character (|n0 - n_c| < 0.1). Samples of calcite and KNSBN ferroelectric crystal have been measured by this method using the single wavelength ellipsometer or the spectroscopic ellipsometer. Reasonable results have been obtained for the KNSBN crystals with |n_0-n_c|< 0.1.