Similarities and Differences between Spatial Coherence Profilometry and White-light Interferometry

Spatial coherence profilometry is a method that uses a Michelson interferometer illuminated by a quasi-monochromatic spatially extended light source to measure the shape of objects. Because of the spatially extended light source, this method takes advantage of spatial coherence of the light. Thus spatial coherence profflometry appears to be a spatial coherence analogy to white-light interferometry which is a reliable and proved method for the measurement of the shape of objects. White-light interferometry usually uses a Michelson interferometer illuminated by a polychromatic point-like light source and so is based on temporal coherence. Though these both measurement methods look similar they show some significant differences. By means of theoretical analysis and experiments we investigate what is similar and where are the differences between these both methods.