Gas-induced smoothing of laser beams studied by interaction with thin foils

R. Benocci (1) , D. Batani (1) , R. Dezulian (1) , R. Redaelli (1) , G. Lucchini (1) , F. Canova (1, 2) , H. Stabile (1, 2) , Jérôme Faure (2) , E. Krousky (3) , K. Masek (3) , M. Pfeifer (3) , J. Skala (3) , R. Dudzak (3) , M. Koenig (4) , V. Tikhonchuk (5) , Ph. Nicolaï (5) , Victor Malka (2)

1 Dipartimento di Fisica "Giuseppe Occhialini" = Department of Physics "Giuseppe Occhialini" [Milano-Bicocca]
2 LOA - Laboratoire d'optique appliquée
3 PALS Research Centre
4 LULI - Laboratoire pour l'utilisation des lasers intenses
5 CELIA - Centre d'Etudes Lasers Intenses et Applications

We studied the process of laser beam homogenization in a gas medium placed in front of a thin metallic foil. Experiments were performed using the Prague PALS iodine laser working at 0.44 µm wavelength and irradiances of about 10^15 W cm^−2. Homogenization was detected both by directly analysing the transmitted laser beam and by studying the shock breakout on the foil rear side. Results show that the gas ionization by the laser pulse induces a strong refraction and produces an effective smoothing of large-scale intensity non-uniformities.

Domains: Optics [physics.optics]

R. Benocci, D. Batani, R. Dezulian, R. Redaelli, G. Lucchini, et al.. Gas-induced smoothing of laser beams studied by interaction with thin foils. Plasma Physics and Controlled Fusion, 2008, 50 (11), pp.115007. ⟨10.1088/0741-3335/50/11/115007⟩. ⟨hal-00501620⟩