基于薄膜干涉滤光片的线性调谐滤光器

A Linear Tuning Filter Base on Thin-Film Interference Filters

基于薄膜干涉滤光片角度调谐的基本原理,提出并实现了一种线性调谐滤光器.利用步进电机控制薄膜干涉滤光片的入射角,通过优化机构装置参量,使步进电机旋转角成为线性控制变量.通过应用多层介质薄膜的膜系特征矩阵以及机构装置的几何关系,从理论上得到了滤光片的峰值波长随步进电机的旋转角之间的变化关系曲线,证明线性调谐滤光器具有可行性.设计了一个包括步进电机控制电路在内的实验装置,在1548～1561 nm的波长调谐范围内,取得了线性误差在±0.6 nm以下的实验结果.

Based on angle-tuned thin-film interference filter, a new linear tuning filter is designed. The idea of the linear tuning filter is to make use of a stepping motor control incidence angle of the filter in this mechanism. By means of optimizing parameters of mechanism, it makes rotary angle of stepping motor become a linear control variable. Through transferring matrix method of multilayer thin-film interference filter and the relation of geometry in the mechanism, the relationship between central wavelength of the filter and rotary angle of stepping motor is calculated theoretically. The results show that the linear tuning filter is feasible. An experimental setup including control circuit of stepping motor has been designed. As a result, the central wavelength offset less than ±0.6 nm is achieved with a tuning range of 1548-1561 nm。