I.A. Vdovichenko - Ph.D. (Eng.), Associate Professor, Department «Physics and Technology of Optical Communication», Nizhniy Novgorod State Technical University n.a. R.Y. Alexseev A.E. Ivanov - Ph.D. (Eng.), Associate Professor, Department «Physics and Technology of Optical Communication», Nizhniy Novgorod State Technical University n.a. R.Y. Alexseev G.I. Shishkov - Ph.D. (Eng.), Professor, Department «Physics and Technology of Optical Communication», Nizhniy Novgorod State Technical University n.a. R.Y. Alexseev V.V. Sherbakov - Ph.D. (Eng.), Associate Professor, Department «Physics and Technology of Optical Communication», Nizhniy Novgorod State Technical University n.a. R.Y. Alexseev. E-mail: physics@nntu.nnov.ru