title: Spatio-spectral structures in high-order harmonic beams generated with Terawatt 10-fs pulses.
abstract: A large international effort is nowadays devoted to increase the energy of the extreme ultraviolet pulses by using high-peak power ultrashort fundamental pulses (Terawatt level). Using such fundamental pulses brings specific constraints that need to be addressed. Here we study high-order harmonic generation in gases with 10 fs pulses at Terawatt peak power and demonstrate that extreme ultraviolet beams can be highly structured and complex in various conditions. We use a single-shot spatially resolved spectral detection and demonstrate direct observation of the spatio-temporal coupling occurring in the generating medium. Clear and reproducible complex spatio-spectral structures are observed in the far field. Similar structures are reproduced with simulations and we show that they are intimately associated to the high nonlinearity of high-order harmonic generation. Those findings are of prime importance for the generation of high-energy attosecond pulses and reveal important issues for their applications.
authors.affiliation: Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 351 cours de la Libération, 33405 Talence Cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Dubrouil
authors.affiliation: Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 351 cours de la Libération, 33405 Talence Cedex, France.
authors.forename: O
authors.initials: O
authors.lastname: Hort
authors.affiliation: Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 351 cours de la Libération, 33405 Talence Cedex, France.
authors.forename: F
authors.initials: F
authors.lastname: Catoire
authors.affiliation: Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 351 cours de la Libération, 33405 Talence Cedex, France.
authors.forename: D
authors.initials: D
authors.lastname: Descamps
authors.affiliation: Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 351 cours de la Libération, 33405 Talence Cedex, France.
authors.forename: S
authors.initials: S
authors.lastname: Petit
authors.affiliation: Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 351 cours de la Libération, 33405 Talence Cedex, France.
authors.forename: E
authors.initials: E
authors.lastname: Mével
authors.affiliation: A.M. Prokhorov General Physics Institute of Russian Academy of Sciences, 38 Vavilova street, Moscow 119991, Russia.
authors.forename: V V
authors.initials: VV
authors.lastname: Strelkov
authors.affiliation: Université de Bordeaux-CNRS-CEA, Centre Lasers Intenses et Applications, UMR 5107, 351 cours de la Libération, 33405 Talence Cedex, France.
authors.forename: E
authors.initials: E
authors.lastname: Constant