Fringe order identification in optical fibre white-light interferometry using centroid algorithm method

A special digital signal processing technique based on a centroid algorithm is presented. It is used to identify the central fringe from the output fringe pattern produced by an optical fibre white-light interferometer system to achieve a large-dynamic-range and absolute phase measurement. A computer simulation and subsequent experimental verification have shown that this technqiue is capable of sustaining a high operating noise level.