An anti-vibration phase demodulation method applied to phase-shifting interferometric

As a high-precision detection technique of surface topography based on the interference theory of light, Phase-Shifting Interferometric is susceptible to vibration from the surrounding environment, which reduces the detection accuracy. In order to reduce the influence of vibration errors and improve the phase demodulation accuracy of measured wavefront, an anti-vibration phase demodulation method applied to Phase-Shifting Interferometric is proposed in this paper. This method first acquires two sequences of interference images with phase shifts of 0 and 𝜋𝜋/2 respectively, uses a digital image stabilization algorithm to suppress the vibration error of each frame in the sequence, and synthesizes two frames of interference images with phase shifts of 0 and 𝜋𝜋/2, respectively. Then, based on these two frames of synthesized images with determined phase shifts, the gradient algorithm and the Schmidt Orthogonal Transform are used for wavefront phase demodulation. The experimental results show that the percentage of pixels demodulated effectively at the truncated interface is more than 90%. Compared with the traditional demodulation method, the number of pixels demodulated effectively (demodulation accuracy) is improved.