1. Slovak Centre of Scientific and Technical Information International Laser Centre, Ilkovičova 3,Bratislava,Slovakia,84104
2. Photonics Institute, Vienna University of Technology,Gusshausstrasse 25-29,Vienna,Austria,1040
3. Lukasiewicz Research Network - Institute of Microelectronics and Photonics, Al. Lotnikow Lotników 32/46,Department of Optical Fiber Technology and Quantum Systems,Warsaw,Poland,02-668