LASER-MATTER INTERACTION IN INTENSE LASER FIELDS

This paper provides a brief review of some processes which happen when an intense laser field interacts with matter, typically 10(12)-10(15) W/cm2. Multiphoton ionization of atoms occurs leading to multiply charged ion production (study of the dynamic of the processes), above-threshold ionization (electron energy measurement) and very high order harmonic generation. Exposed to a strong laser field, an atom can radiate many odd harmonics of the pump field, with a constant amplitude up to an extremely high order. Up to the 135th harmonic (160 eV) of a 1053 nm Nd-Glass laser in a Ne gaz jet has been very recently observed. Finally, laser-matter interactions at 10(17)-10(19) W/cm2, an intensity range now reached due to new short pulse laser technology, will be discussed.