Abstract

Phase-shift interferometry (PSI) techniques have been widely used in modern phase-measurement instruments. The PSI technique is based on varying the phase difference between two beams in a known manner, and deriving the initial phase using three or more intensity measurements. The most common way to vary the phase difference between two beams is to apply a voltage to a piezoelectric (PZT) transducer upon which the reference mirror is mounted. The voltage applied is a ramp voltage or a step voltage with equal period and equal increment.

© 1986 Optical Society of America