为了精确定位白光干涉条纹的零光程差位置，采用空间频域算法通过傅里叶变换提取白光干涉信号中心波长的相位信息并结合包络中心算法去除相位模糊从而实现零光程定位。实例测量了具有相位突变的计算全息元件的表面轮廓，其平均刻蚀深度为1.63 μm。测量表面形貌连续分布的微透镜阵列，0.32 mm×0.32 mm 视场内表面PV 为370.99 nm，RMS 为62.4 nm。空间频域算法能够有效定位白光干涉零光程差位置，适合于测量微观表面轮廓分布。

In order to find zero Optical Path Difference (OPD) position with high precision in white light interferometry, the algorithm of spatial frequency domain analysis is studied. The phase information of the nominal center wavelength is acquired from white light interference intensity signal using Fast Fourier Transform (FFT). The phase illegibility is removed to determine zero OPD position according to the coherence peak. The Computer Generated Holograms (CGH) with a depth of 1.63 μm is measured. A continuous surface of the micro lens array tested with Frequency Domain Analysis(FDA) has a PV value of 370.99 nm and a RMS value of 62.4 nm. By obtaining the position of the zero-order white light fringe, the FDA method can be used to measure the micro surface profile.