FRINGE PATTERN-ANALYSIS IN LOW-QUALITY INTERFEROGRAMS

Mechanical vibrations in the frame of an interferometer can introduce a space-dependent factor throughout an interferogram, making its analysis quite difficult. This factor is formally equivalent to the modulus of the complex degree of coherence in the case of quasimonochromatic light. A simple method for retrieving the underlying phase distribution and detecting small perturbations is presented. Introducing an appropriate correction for the above-mentioned factor, good sensitivity is also achievable in noisy environments