基于低相干光干涉的相位成像实验系统

Phase Imaging Experimental System Based on Low Coherence Optical Interferometry

设计了一种基于低相干光干涉的相位成像实验系统,系统主要包括低相干光光源、光纤迈克尔逊干涉仪和光谱仪。由光谱仪采集探测光和参考光的干涉光谱,对其进行傅里叶变换得到卷绕相位,分别用数值解卷绕、合成波长法及干涉光谱逼近法进行解卷绕。对分辨率板和阶差规进行了相位成像,对比了数值解卷绕、合成波长法及干涉光谱逼近法的优缺点。实验结果显示,数值解卷绕和干涉光谱逼近法具有较高分辨率,干涉光谱逼近法适用于较大测量范围的相位解调。

A phase imaging experimental system based on low coherent optical interferometry is established.The system mainly includes alow-coherent light source,an optical-fiber Michelson interferometer and a spectrometer.The interference fringes of the sample light and the reference light are collected by the spectrometer,and the wrapped phases are obtained by the Fourier transform algorithm.And then,the interference fringes are unwrapped by the numerical unwrapping method,synthetic wavelength method and interference spectrum approximation method.The phase imaging of a resolution plate and a step gauge is conducted to demonstrate the differenceamong the three phase calculation methods.The experimental results show that the numerical phase-unwrapping method and the interference spectral approximation method have higher resolution,and the interference spectral approximation method is suitable for the phase demodulation with a larger measurement range.