1. Lebedev Physical Institute, 119991 Moscow, Russia
2. School of Natural Sciences and Mathematics, Ural Federal University, 620000 Ekaterinburg, Russia
3. Laser and Optoelectronic Systems Department, Bauman Moscow State Technical University, 2nd Baumanskaya St. 5/1, 105005 Moscow, Russia
4. Institute of Physics, Saratov State University, 410012 Saratov, Russia