V. V. Biryukov – Dr.Sc. (Eng.), Professor, Department of Physics and Technology of Optical Communication, Nizhny Novgorod State Technical University n.a. R.E. Alekseev

E-mail: birukovvv@mail.ru

V. A. Grachev – Ph.D. (Eng.), Associate Professor, Department of Physics and Technology of Optical Communication,

Nizhny Novgorod State Technical University n.a. R.E. Alekseev

S. G. Lobin – Post-graduate Student, Department of Physics and Technology of Optical Communication, Nizhny Novgorod State Technical University n.a. R.E. Alekseev