INCREASING OF HOLOGRAPHIC INTERFEROMETER SENSITIVITY BY DIGITAL METHODS

Abstract

The development of methods for increasing the sensitivity of interferometers intended for studying complex phase media, which are characterized by abrupt changes in internal inhomogeneities, is a very urgent task. The aim of the study, the results of which are presented in the article, is a theoretical analysis of the possibility of improving the sensitivity of the output data of a holographic interferometer using digital methods of processing optical information. The research results showed that the presence of digital information about the object and reference waves and about the interference pattern recorded by the CCD matrix allows performing various mathematical operations on these data, after which they can again be displayed on the screen, i.e., visualized. These operations can be carried out both in the sections from the object to the output plane, and at the output of the system, directly with the intensity distribution, which is fixed by the CCD matrix. A sequence of numerical operations is proposed, which makes it possible to increase the sensitivity of the holographic system by a factor of 2m , where m  0,1, 2, 3,.... It is also shown that the increase in sensitivity according to the indicated scheme is limited only by possible speckle noise, which can worsen the contrast of the fringes of the interference pattern. The proposed method for increasing the sensitivity of the interferometer, in contrast to the known ones, does not rely on hardware changes in interferometric systems, which is associated with high costs, but digitally improves the characteristics of the output data of low-sensitivity interferometers. The results of the work can be used in studies of complex phase media.