1. Institute of Physics, AJD Czestochowa, Al. Armii Krajowej 13/15, Czestochowa, Poland, Institute of Applied Physics and Institute of Optoelectronics, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa, Poland, and Laboratoire de Physique Appliquée et d'Automatique, Université de Perpignan, Perpignan, France