Phase or fringe scanning using a phase scanning device such as a piezo-electric device for determining the surface properties of objects, such as detection of wave front aberrations of less than one tenth of a wavelength

摘要

Phase or fringe scanning method has the following steps: displacement of an object and a reference relative to each other using a phase scanning device, attainment of fringe data for three or more phase displacement positions and determination of the phase of the object by analysis of the fringe data images. The position data of the three phase positions is calculated and all or part of the fringe data, superimposed with carrier fringes, are subjected to an arithmetic operation to execute a phase analysis and determine object phases. An Independent claim is also included for a phase scanning device for determining the phase of an object.