1. Moscow Institute of Physics and Technology, National Research University, 141700 Dolgoprudny, Russia
2. Terahertz Center, University of Regensburg, D-93053 Regensburg, Germany
3. Physics Department, Moscow State Pedagogical University, 119435 Moscow, Russia
4. National Research University Higher School of Economics, 101000 Moscow, Russia
5. Prokhorov General Physics Institute, RAS, 119991 Moscow, Russia
6. Ioffe Institute, 194021 St. Petersburg, Russia
7. ITMO University, 197101 St. Petersburg, Russia
8. CENTERA Laboratories, Institute of High Pressure Physics, PAS, 01-142 Warsaw, Poland