Affiliation: | a Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warsaw, Poland b Institute of Applied Physics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warsaw, Poland c Institute of Physics, WSP, Al. Armii Krajowej 13/15, 42-201, Cz?stochowa, Poland |