中文摘要：

首先分析了光线通过薄膜的理论及特点，在此基础上，采用透镜、分束棱镜、滤光片以及新型半导体光电位置敏感器件，设计了一种新型透明体厚度光电检测仪。该仪器中的光学系统设计，采用双光路消漂移方法，消除了光束的漂移等不稳定因素；信号处理电路采用高精度、低温漂放大器等元器件，最大程度地消除了热噪声；对入射光线、被测体、探测器三者之间的相对位置进行了最优化设计。最后，对该仪器的结构、特点以及产生的误差进行了分析，给出了几个重要结论。

英文摘要：

Firstly the theory and characteristics of light passing the film are analysed. Then, designed is a new type of photoelectric clarity body thickness detection instrument including several components, such as lens, a splitting prism, a filter, a new photoelectric detector. The instrument uses a double optical pass dispel excursion method for the optical system design, eliminating light excursion. And the signal processing circuit applies the drift amplifier with characteristics of high precision and low temperature, eliminating the heat noise extensively. The relative position of the three factors of incident light, measured object and detector is optimized. The structure, characteristic and error of the instrument are analysed, and several important conclusions are obtained.