1. Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
2. Laser Research Center, Vilnius University, Saulėtekio Av. 10, 10223 Vilnius, Lithuania
3. Department of Characterization of Materials Structure, Center for Physical Sciences and Technology—FTMC, Saulėtekio Av. 3, 10257 Vilnius, Lithuania
4. Department of Organic Chemistry, Center for Physical Sciences and Technology (FTMC), Saulėtekio Av. 3, 10257 Vilnius, Lithuania
5. Department of Physics, University of Exeter, Exeter EX4 4QL, UK