title: Controlling high harmonics generation by spatial shaping of high-energy femtosecond beam.
abstract: We demonstrate controlled high-order harmonic generation in gas using high-energy femtosecond pulses (50 fs-50 mJ on target) by performing spatial shaping of the terrawatt fundamental laser beam. We have developed a two optical paths mirror that can withstand high power and shape the pump beam into a quasi-flat-top profile (super Gaussian) near focus. We observe clear signatures of the spatial shaping on the harmonic beam in terms of profile, divergence, level of signal, and spectrum. The harmonic generation in neon with a quasi-flat-top beam results in a broadband extreme UV beam with extremely low divergence (~340 μrad).
authors: Centre Lasers Intenses et Applications, Université de Bordeaux-CNRS-CEA, 351, cours de la Libération, 33405 Talence Cedex, France. dubrouil@celia.u‐bordeaux1.fr
authors: A
authors: A
authors: Dubrouil
authors: Y
authors: Y
authors: Mairesse
authors: B
authors: B
authors: Fabre
authors: D
authors: D
authors: Descamps
authors: S
authors: S
authors: Petit
authors: E
authors: E
authors: Mével
authors: E
authors: E
authors: Constant