1. Department of Physics of Electronic Phenomena, Gdańsk University of Technology, ul. G. Narutowicza 11/12, 80-233 Gdańsk, Poland
2. Gdynia Maritime University, ul. Morska 81-87, 81-225 Gdynia, Poland
3. Institute of Experimental Physics, University of Gdańsk, ul.
Wita Stwosza 59, 80-952 Gdańsk, Poland