<title>Zone plates application in the Talbot shift interferometer</title>

Abstract

A comparative theoretical and experimental examination of Talbot effect behind linear, circular gratings with constant period and zone plates is carried out. Features connected both with the shape and with the period of dashes are detected. It is shown that the quality of the self-image of gratings is determined by the boundaries of the range of spatial frequencies, represented in the image. The experimental results of the phase objects visualisation with the help of the Talbot interferometer with zone plates are given. The zone plate Talbot interferometer was first used for the visualization of thermal inhomogeneity in the active laser element induced by pumping radiation. A registered moire pattern allows clearly observing the appearance of distortions and its kinetics.