Improving the phase reconstruction accuracy of simultaneous phase-shifted lateral shearing interferometry using a polarization redundant sub-region interpolation method

Abstract

In a simultaneous phase-shifted lateral shearing interferometry, a division of focal plane polarization camera is generally used as the phase-shifting device. However, acquiring simultaneous phase-shift interferograms in a single frame suffers from a lack of spatial resolution, significantly affecting the phase reconstruction accuracy. A polarization redundant sub-region interpolation (PRSI) method is proposed to solve this problem. This interpolation method distinguishes smooth regions from stripe fringe regions by calculating the polarization redundancy error of the synchronous phase shift interferogram. After sub-regional processing, resolution reconstruction is performed in the smoothed area using a fast convolutional bilinear interpolation method. In the streak detail region, the resolution reconstruction is performed based on the strength of the correlation between the orthogonal and non-orthogonal polarization channels crossing the streak region. The PRSI method can quickly reconstruct the lost pixels and accurately recover the stripe detail information. Experiment results show that the proposed interpolation method outperforms the existing dominant methods in terms of visual reconstruction effect and quantitative index of phase reconstruction.

Parallel Phase-Shifting Digital Holographic Phase Imaging of Micro-Optical Elements with a Polarization Camera

“…Because the digital hologram recorded with the polarization camera loses spatial resolution, the resolution is only 1/4 of the resolution of the original polarization image taken with the polarization camera. To correct the pixel mismatch error, it is necessary to interpolate the four phase-shifting holograms [28]. After interpolation, the resolution of the four phase-shifting holograms with high resolution is the same as that of the original polarization image.…”