1. International Research and Education Centre for Physics of Nanostructures, ITMO University, Kronverksky pr. 49, 197101 Saint Petersburg, Russia
2. Research Park, Saint Petersburg State University, Universitetskaya emb. 7–9, 199034 Saint Petersburg, Russia
3. Department of Materials Science and Engineering, and Centre for Functional Photonics (CFP), City University of Hong Kong, Kowloon, Hong Kong SAR 999077, China