<title>Instantaneous Phase Measuring Interferometry</title>

Abstract

Conventional phase measuring interferometry normally requires one-half to sixty seconds acquisition time, limiting measurement to stationary phenomenon such as optical element wavefronts. We have developed an instantaneous PMI that measures displacements at one point to a resolution of 0.003 microns. We will describe this instrument and an interferometer measuring phase to lambda/2000 with a measurement aperture of less than one microsec. Also described is an attached system for analysing and displaying wavefronts at up to 10 Hz.