Demodulating interferograms with non-uniform amplitude variations for precision non-contact optical profilometry

Abstract

In this paper, we propose a fringe analysis method to address the problem of phase retrieval from interferogram corrupted with fringe amplitude non-uniformity, and show its practical application for nanoscale surface profilometry. The proposed method relies on the implementation of second order optimization combined with total variation regularization using graphic processing unit based computing. The capability of the proposed method is demonstrated via numerical simulations by inducing different amplitude non-uniformity patterns in the interferograms and through experimental non-invasive surface topography using diffraction phase microscopy.