White light scanning interferometer with simultaneous phase-shifting module

A simultaneous phase-shifting white light scanning interferometer comprises a white light scanning interferometer, a simultaneous phase-shifting module, and a scanner. Light from a short coherence length light source may be polarized and then split, by a polarization type beam-splitter, into orthogonally polarized reference and test beams. The simultaneous phase-shifting module comprises a plurality of detectors, allows for controlled phase shifts between the reference and test beams, and creates at least three independent interferograms, each with different phase shifts between the reference and test beams. The scanner translates the simultaneous phase-shifting module with respect to an object under measurement.