Spatial-phase-shift imaging interferometry using a spectrally modulated white light source

An extension of the white light spatial-phase-shift (WLSPS) for object surface measurements is described. Using WLSPS, surface measurements can be obtained from any real object image without the need of a reference beam, thus achieving inherent vibration cancellation. The surface topography is obtained by acquiring multiple images of an object illuminated by a spectrally modulated white light source and using an appropriate algorithm. The modulation of the light source obviates the need for the continuous phase delay to obtain the interferograms.