提出一种多波长显微干涉光强一致性的控制方法。将光强可调的白光LED作为多波长光源,在显微干涉光路中加入光强探测器,将从不同滤光片出射光的光强实时反馈到STM32单片机中,通过PID(Proportion Integration Differentiation)控制快速调整LED输出光强,实现不同波长光强的一致性,进而得到灰度分布一致的多波长干涉图像。实验结果表明,本文方法能够使不同波长的光强快速准确地稳定在设定值,将对应的不同波长干涉图像对比度误差从18%减小到2%。

This study presents a method for controlling the intensity consistency of multi-wavelength micro-interferometry. A white LED with tunable intensity is used as the multi-wavelength source. A detector is placed in the micro-interferometry optical path to detect intensity of light emitted from different filters, and the signal is fed back to an STM32 microcontroller in real time. Light intensities from different optical filters are quickly adjusted to be consistent using PID (proportion integration differentiation) control method and multi-wavelength interferograms with consistent gray distribution are obtained. The experimental results show that the presented method can quickly adjust the illumination intensity at different wavelengths, accurately stabilize at the set value, and reduce interferogram contrast error from 18% to 2%.