Surface measurements by white light spatial-phase-shift imaging interferometry.

A novel method of common-path imaging interferometry, the White Light Spatial-Phase-Shift (WLSPS) for object surface measurements, is discussed here. Compared to standard White Light Interferometry (WLI), which uses a reference mirror, the interferometry of WLSPS is obtained by creating manipulations to the light wavefront reflected from an object's surface. Using this approach, surface measurements can be obtained from any real object image, and do not need to be taken directly from the object itself.