1. Gdansk University of Technology, Faculty of Electronics, Telecommunications & Informatics, G Narutowicza 11/12, 80–233 Gdansk, Poland.
2. GR Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
3. Departamento de Fisica, Universidade Federal de Ouro Preto, MG 35400–000 Brazil
4. Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA