1. Department of Physical Optics and Applied Informatics, Faculty of Physics, Belarusian State University, Nezavisimosti Avenue, 4, 220030 Minsk, Belarus
2. Department of Differential Equations and System Analysis, Faculty of Mechanics and Mathematics, Belarusian State University, Nezavisimosti Avenue, 4, 220030 Minsk, Belarus
3. Faculty of Physics, The University of Illinois at Chicago, 845 W Taylor Street, Chicago, Illinois 60607, United States