弱吸收多层薄膜消光系数的反演

从窄带干涉滤光片的峰值透射率测量可以直接反演出弱吸收薄膜的消光系数，从而得到一种能简易而又精确地评价多层薄膜微弱吸收的新方法. 推导了弱吸收窄带干涉滤光片的吸收表达式， 阐述了确定弱吸收薄膜消光系数的基本原理.以离子束溅射的Ta₂O5/SiO₂波分复用滤光片为例，分析了这种评价方法的基本精度. 关键词： 光学测试 离子束溅射 光学薄膜干涉滤光片 消光系数

Determination of the extinction coefficient of a weakly absorbing multilayer system

Based on a measured peak transmittance of a narrow band filter, the extinction coefficients of weakly absorbing thin films in a multilayer system can directly be calculated. This is a new method used for determination of the extinction coefficients of thin films in a weakly absorbing multilayer system with very easy to do and very high precision. The absorbing expression in a weakly absorbing interference narrow band filter is deduced. The principle of determination of the extinction coefficient is illustrated and the precision of the calculated extinction coefficient in a Ta₂O₅/SiO₂ filter used in a dense wavelength division multiplexing system is analyzed.