Home – Home – Jornals – Avtometriya 2023 number 5

The Fraunhofer diffraction phenomena in coherent light on an extended object of constant thickness in the form of a volumetric asymmetric edge with a bevel and a flat reflecting (gray) inner surface of the object, characterized by the modulus of the amplitude coefficient of light reflection and the phase shift in the reflected wave, are investigated using the model of equivalent transparencies. It is shown that the field in the far zone can be represented in the form of two components: transmitted and reflected, the former corresponding to diffraction of light at an absolutely absorbing asymmetric edge, and the latter describes diffraction phenomena at a volume structure in the form of a biplanar slit illuminated by a plane light wave. On the basis of a constructive approximation of the Fresnel integral function, an expression for the spectrum of the object is obtained in analytical form, which allows studying the behavior of fields in the far-field zone. It is shown that, in the case of a large object obliqueness, the main contribution to the field is given by the reflected component. Methods of determining the geometric parameters of the object by measuring the position of the central maximum of the reflected component and its effective width are proposed.