Apparatus, techniques and systems for implementing an optical interferometer to measure surfaces, including mapping of instantaneous curvature or in-plane and out-of-plane displacement field gradients of a sample surface based on obtaining and processing four optical interferograms from a common optical reflected beam from the sample surface that are relatively separated in phase by .pi./2.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
The U.S. Government has certain rights in this invention pursuant to Grant No. DE-FG52-06NA26209-T-103505 awarded by Department of Energy and Grant No. N00014-06-1-0730 awarded by Office of Naval Research.