Theoretical limits of scanning white-light interferometry signal evaluation algorithms.

Scanning white-light interferometry is widely used for the microstructure analysis of technical and biological specimens. For each pixel in the focal plane of the apparatus a white-light interferogram is acquired and evaluated by means of an algorithm. We discuss some properties of mathematically optimal evaluation methods and the best possible achievable resolution derived therefrom depending on the setup parameters. A comparison of the results to one of the algorithms described in the literature is given.