High-Precision Dynamic White-Light Interferometry

White-light interferometry has the advantages of high accuracy and non-contact measurement, which is an important measurement method in the field of ultra-precision machining. To tackle the problem that white-light interferometry is easily affected by environmental vibration, dynamic vertical scanning interferometry (DVSI) is proposed. This method divides the white-light interferometric optical path into two imaging channels to generate a quasi-monochromatic light interferogram, which is phase-shifted synchronously with the white-light interferogram. We obtain the actual phase-shift scanning position by processing the quasi-monochromatic light interferogram through the phase-tilt iteration (PTI), after which the coherence peak of the white-light interference signal is located and the coarse topographic distribution is calculated. The local least square (LLS) is used to calculate the fine phase distribution. The coarse topographic distribution and fine phase distribution are combined to recover the threedimensional topography of the tested sample. The method is verified through numerical simulation and experimental comparison, and the results show that the method has good vibration-resistant performance.