1. Institute of Nuclear and Physical Engineering at the Faculty of Electrical Engineering and Information Technology of Slovak University of Technology, Bratislava 812 19, Slovakia
2. International Laser Center, Bratislava 841 04, Slovakia
3. Department of Experimental Physics of the Faculty of Mathematics, Physics and Informatics of the Comenius University in Bratislava, Bratislava 842 48, Slovakia
4. Institute of Electrical Engineering at the Faculty of Electrical Engineering and Information Technology of the Slovak University of Technology, Bratislava 812 19, Slovakia
5. Institute of Electronics and Photonics at the Faculty of Electrical Engineering and Information Technology of the Slovak University of Technology, Bratislava 812 19, Slovakia