Direct phase determination in hologram interferometry with use of digitally recorded holograms

TLDR

A new method of phase determination in hologram interferometry is described. The method uses Fresnel holograms of undeformed and deformed states recorded on a CCD, reconstructs them digitally without lenses, and compares their phases to directly determine the interference phase. The approach demonstrates that both intensity and phase can be calculated from digitally sampled holograms.

Abstract

A new method of phase determination in hologram interferometry is described. The Fresnel holograms, which represent the undeformed and the deformed states of the object, are generated on a CCD target and stored electronically. No lens or other imaging device is used. The reconstruction is done from the digitally stored holograms with mathematical methods. It is shown that the intensity as well as the phase can be calculated from the digitally sampled holograms. A comparison of the phases of the undeformed and the deformed states permits direct determination of the interference phase.