Complex Interferometry: How Far Can You Go?

Abstract

Classical interferometry is one of the key methods in laser-produced plasma diagnostics. Its more advanced version, which allows recording and subsequent reconstruction of up to three sets of data using just one data object - a complex interferogram – was developed in the past and became known as complex interferometry. Employing this diagnostics, not only the usual phase shift, but also the amplitude of the probing beam as well as the fringe contrast (leading directly to the phase shift time derivative) can be reconstructed simultaneously from such a complex interferogram. In this paper attention will be paid to the analysis of practical limits of this diagnostics in its application for the reconstruction of all three above mentioned quantities taking advantage of the corresponding reference interferogram availability. It will be shown that even in the case of a not particularly high diagnostic beam quality these quantities can be reconstructed with a surprisingly good accuracy provided both the diagnostic beam as well as the corresponding optical line maintain reasonable stability between the signal and the reference shots.