Extraction of interference phase in frequency-scanning interferometry based on EMD and Hilbert transform
Extraction of interference phase in frequency-scanning interferometry based on EMD and Hilbert transform
复制标题
基于EMD和Hilbert变换的扫频干涉测量中干涉相位的提取
作者：
WEN DENG;ZHIGANG LIU;ZHONGWEN DENG;XINGYU JIA;ZHIYONG WANG
在可调谐激光器频率扫描干涉测量中，非线性光学频率扫描是不可避免的，它严重影响了干涉信号相位提取的精度。为了解决这个问题，我们提出了一种基于经验模式分解和希尔伯特变换的相位提取算法。该方法能有效地消除光频扫描非线性的影响。通过仿真和实验验证了该方法的有效性和稳定性。当采样频率为5MHz时，测量系统的单周期相对误差和标准偏差分别为0.6%和0.7 μm。
Nonlinear optical frequency scanning is inevitable in frequency scanning interferometry with tunable lasers and seriously reduces the accuracy of interference signal phase extraction. To address this, we propose a phase extraction algorithm based on empirical mode decomposition and Hilbert transformation. The method can effectively eliminate the influence of the optical frequency scanning nonlinearity. The validity and stability of the method have been verified through simulations and experiments. Moreover, the single-cycle relative error of the phase between adjacent peaks and the standard deviation of the measurement system improved to 0.6% and 0.7 μm, respectively, with a 5-MHz sampling rate.