**Author details**

Mihai Oane1 , Rareş Victor Medianu2\* and Anca Bucă<sup>1</sup>

\*Address all correspondence to: vrmlaser@gmail.com or rares.medianu@nanofizica.ro

1 National Institute for Laser, Plasma Radiation Physics, Bucharest, Romania

2 University of Bucharest, Faculty of Physics, Bucharest, Romania
