Fast algorithm for surface profiling by white-light interferometry using an optical filter with symmetric spectral distribution

A fast algorithm for surface profiling by white-light interferometry using an optical filter with a symmetric spectral distribution is proposed. The algorithm uses a novel function in order to detect the maximum position of the interferogram while most of conventional methods use the envelope function or its square. By utilizing a sampling theorem, sampling interval is extended to more than twice the widest interval used in conventional methods. Since the reconstruction formulae in the algorithm are very simple, it keeps low computational costs. Simulation results using a theoretical model with and without noise show a good performance of the new algorithm