Optical Methods in Fluid and Solid Dynamics Research

Abstract

The Majority of optical diagnostic methods, which are used in mechanics, are based mostly on ideas of classical-geometrical optics that is on concepts and methods developed practically by the end of the 19th century. Since the introduction of the Max Planck quantum hypothesis a new period came on in the development not only of physics, but also of physical optics. It can be said without any exaggeration that a decesive turn in the development and in the exploitation of optical methods in the whole field of physics began just at that time, when the relation between atomic structure and spectrum was brought into optics, which enabled to take account of the proper character of light. So was gained the poe8ibility to explain a number of optical phenomena, some of which, especially light diffraction, have great significance even for the theoretical and practical determination of fundamental charakteristics of optical instruments, e.g. their resolution power. Exploitation of both geometrical and wave optics gave the basis for derivation of principles for new diagnostic methods as well.