K. I. Kisilenko – Assistant, Department of Physics and Technology of Optical Communication, Nizhny Novgorod State Technical University n.a. R.E. Alekseev

E-mail: physics@nntu.ru

E. P. Timofeev – Ph.D. (Eng.), Professor of Department of Physics and Technology of Optical Communication, Nizhny Novgorod State Technical University n.a. R.E. Alekseev