Affiliation: | 2. St. Petersburg National Research University of Information Technologies, Mechanics and Optics (ITMO University), St. Petersburg, Russia;3. Institute of Physics, University of Freiburg, Freiburg, Germany;4. Institut Charles Sadron, Université de Strasbourg and CNRS, Strasbourg Cedex, France;5. Laboratory of Physics, Lappeenranta University of Technology, Lappeenranta, Finland |