高精度快速光栅光谱扫描波长定位方法研究

Quick and High Accuracy Wavelength Setting Method for Grating Spectrometer

传统光栅扫描式光谱仪器由于机械结构的限制,无法达成高精度扫描和高速扫描的统一。本文针对电机直接驱动光栅的扫描结构,提出了一种采用激光、位置敏感探测器PSD以及底面为正多边形的棱柱反射扫描镜的全新主动光电扫描反馈光栅角度位置的结构和方法,目的是在保证快速扫描的同时,利用主动光源经多面反射镜反射形成光斑在PSD上的扫描,从而精确传感和反馈光栅的转动来确保波长扫描的精度。系统由步进电机直接带动光栅快速转动产生扫描光谱,由激光器、PSD和多面反射扫描镜构成主动式光栅角位置反馈系统,对光栅转角进行高精度快速测定,保证系统的扫描精度和速度,初步实验取得了比较满意的结果。

For the structure limit of traditional wavelength scanning systems based on screw mandrel and step motor,they cannot simultaneously work both accurately and quickly.A new active opto-electrical feed-back measurement system based on laser,position sensitive detector and multilateral prism mirror is proposed in this paper.The grating is driven by a step motor directly and its rotational position is measured accurately by the active opto-electrical feed-back measurement system.The purpose of the new strategy is to make the wavelength scanning system work not only accurate but also quick.The elementary experimental results are satisfied.