“…In our previous works, we considered the peculiarities of the diffraction pattern by a slit in a situation where there is not a vacuum behind the screen, as in the fundamental theory of diffraction [1][2][3][4], but a material medium. First, we analyzed the features of the diffraction pattern during the penetration of an electromagnetic wave into a medium with ε ≠ 1 through a round hole [5]. After that, in [6], we considered diffraction in a conventional anisotropic optically birefringent medium and showed that not one, but two series of maxima and minima are formed.…”