波片相位延迟量的测量与快轴的标定

本文提出用空心轴步进电动机带动待测波片调制输出光强，单片机控制步进电动机并同步采样输出光强的光电信号，通过USB接口将采样的光电信号数字量传给上位机，上位机根据步机电动机的时钟脉冲和采样光电信号，求出波片相位延迟的方法。同时提出利用已知四分之波片快轴标定待测波片快轴的新方法。对该方法的不确定度进行了分析。设计制作了实验装置，测量结果表明，四分之波片相位延迟测量的不确定度小于2°。

Measuring of phase retardation and calibration of fast axis of wave plates

A novel means is propesed to measure phase retardation of wave plates.A hollow axle stepping motor rotates the wave plate and modulates output light intensity, while the single chip computer controls the stepping motor and synchronously samples optical and electric signals of output intensity. Once the sampled signal, s are transmitted to the superior computer by USB interlace,according to the stepping motor time pulse and the sampled signals, the phase retardation of the wave plate can be obtained by the superior computer. Moreover,a new approach to calibrate the fast axis of the quarter wave plate is proposed,in which the uncertainty is analyzed.The experimontal result shows that the phase retardation of the quarter wave plate is less than 2 degree.