1. Nanophotonics Lab, Saint Petersburg National Research Academic University of RAS, 194021 St. Petersburg, Russia
2. Peter the Great St Petersburg Polytechnic University, 195251 St. Petersburg, Russia
3. A. F. Ioffe Physical-Technical Institute of RAS, 194021 St. Petersburg, Russia
4. Optoelectronics Research Centre, Tampere University of Technology, 33720 Tampere, Finland