Coherence Scanning Interferometry refers to a type of 3D imaging interference microscopy technique, in which measurement of a surface profile of an object is based at least in part on a localization of interference fringes produced by the interference of a reference wave and a measurement wave reflected from the object's surface. Conceptually, the interference signal recorded by a detector pixel includes interference fringes modulated by a coherence envelope. Thus, the interference signal including the fringes contains two pieces of information regarding the surface profile of the object: the localization of the fringes (the coherence information) and the phase of the quasi-periodic oscillations (the phase information). Local surface height information can be calculated from the recorded interference signals based on the features of the modulation envelope such as the peak signal or centroid (coherence profiling) or based on the phase of the interference fringes (phase profiling).
USPTO Backgrounds
USPTO Backgrounds