FRINGE BEATING EFFECTS INDUCED BY MISALIGNMENT IN A WHITE-LIGHT INTERFEROMETER

The profile of the interference fringe packet obtained in interferomet ry, especially in the topical area of white-light interferometry, may be dramatically altered by the presence of the so-called 'fringe beati ng effect' due to the poor quality of the collimation lens or the misa lignment of the optical arrangement. In the worst cases, the peak valu e of the central fringe will be equal to or even less than that of the other fringes and in consequence will give an erroneous result for th e determination of the central fringe position in the visibility profi le. This effect is considered using a simple computer simulation model and the results both from the computer simulation and from experiment are discussed and compared to find means of eliminating such effects.