光学相干层析技术在光学表面间距测量中的应用

搭建了适于镜头中光学表面间距测量的实验装置,用于非接触高精度测量镜面间距.该装置以光纤型时域光学相干层析系统为基础,通过光学表面的层析成像精确测量其相对位置.对样品扫描装置进行了改进,利用高精度导轨移动光纤准直器来移动成像范围,实现对不同深度光学表面的层析成像.利用实验测量系统完成了对空气间隙样品及已装调好镜头的光学表面间距的测量,其中空气间隙样品的测量值为6.026mm,用游标卡尺得到的对比测量值为6.02mm;对镜头关键参数空气间隙的测量值为10.750mm,其设计值为(10.7±0.03)mm.实验系统误差为3.871μm,测量灵敏度为10.5μm.结果显示该方法具有非接触、高精度、高灵敏度的特点.

Application of optical coherence tomography to distance measurement of optical surface

A measuring system based on optical coherence tomography was established to measure the distance of optical surfaces non-contactly.The system was developed by modifying the sample scanning device based on a time-domain optical coherence tomographic system.The tomographic images of optical surfaces in different depths were acquired by moving the fiber collimator in sample arm through a high precision guide.The distance of an air gap sample and a lens were measured by using this system.Results show that the measured value of air gap sample is 6.026 mm while it is 6.02 mm by using a vernier caliper.Furthermore,the measured value of air gap in the lens is 10.750 mm while its design value is(10.7±0.03) mm.The systematic error is 3.871 μm and the sensitivity is 10.5 μm.The measurement method is characterized by non-contact,high precision,and high sensitivity,and has great potential in optical material testing.