Abstract

Instruments utilizing Phase Shifting Interferometry (PSI) principles are used extensively in precision surface metrology when a non-contact method of surface characterization is required. PSI entails making point to point measurements of the phase difference between a test and reference beam of an interferometer. These phase differences are assumed to be produced from small height changes in the test surface. If the reference surface profile is accurately known, the calculated height differences represent deviations from the reference profile and the test surface profile can be reconstructed therefrom.

© 1992 Optical Society of America