Numerical features of modeling plane wave diffraction by plasma microstructures employing the first Rytov approximation

In the study, we concern the features of modeling a diffraction equation obtained when solving the scalar Helmholtz wave equation in the parabolic and first Rytov approximations. The task is considered in the 2D case for a plane wave transmitted through a micron-sized plasma object. We develop a comprehensive guide for choosing optimal calculation conditions to make the employed modeling procedure be the most efficient and computationally inexpensive. Methods for controlling calculation errors are presented as well. The intensity and phase shift maps are simulated for the diffracted wave in the object's near-field region and analyzed in view of the observed regularities. The applicability of the parabolic and first Rytov approximations is examined in a numerical experiment depending on the radiation wavelength and object size. The results of the study can be useful to implement diffraction imaging techniques aimed at gaining insights into the optical properties of rapidly evolving phase objects.