Quantitative Analysis Of Transient Events By ESPI

Two new techniques of quantitative analysis of ESPI patterns obtained while testing transient event are presented. The first one uses an exact solution of four intensity equations (speckle patterns), that removes the effect of the random speckle distribution of the phase and the contrast respectively. It gives the possibility of high accuracy phase retrieving if the stability of the system is assured. In the second technique the speckle interferometer is modified by introducing a phase grating between the object and the interferometer. The grating separates three (or two) phase shifted images of object in space . This enables transient condition of an object to be captured while allowing full quantitative phase measurement to be performed. This technique may be used for real time measurements although phase is retrieved with low accuracy. The recomendation for the engineering application of the methods of automatic analysis of ESPI interferograms are given.