1. Institute of Electronic Structure and Laser, Foundation for Research and Technology-Hellas 1 , Heraklion 70013, Greece
2. Department of Materials Science and Technology, University of Crete 2 , Heraklion 70013, Greece
3. Department of Physics, University of Patras 3 , Patras 26504, Greece
4. Institute of Chemical Engineering Sciences, Foundation for Research and Technology-Hellas 4 , Stadiou str Platani, Patras 26504, Greece
5. Universite de Toulouse, INSA-CNRS-UPS, LPCNO 5 , 135 Av. Rangueil, 31077 Toulouse, France
6. Ioffe Institute 6 , St.-Petersburg 194021, Russia
7. University of Antwerp 7 , Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
8. Department of Physics, University of Crete 8 , Heraklion Crete 71003, Greece
9. School of Physics, Department of Solid-State Physics, Aristotle University of Thessaloniki 9 , Thessaloniki 54124, Greece