[1] TEI Crete Heraklion, Ctr Mat Technol & Photon, Iraklion 71004, Greece
[2] TEI Crete Heraklion, Sch Appl Technol, Elect Engn Dept, Iraklion 71004, Greece
[3] Univ Crete, Dept Mat Sci & Technol, Iraklion 71003, Crete, Greece
[4] Univ Crete, Dept Phys, Iraklion 71003, Crete, Greece
[5] Fdn Res & Technol FORTH Hellas, IESL, POB 1385, Iraklion 70013, Crete, Greece
[6] Technol Educ Inst Crete, Dept Elect Engn, Romanou 3, Khania 73100, Greece
[7] Univ Crete, Crete Ctr Quantum Complex & Nanotechnol, Dept Phys, Iraklion 71003, Greece