%0 Journal Article %T Spatial Properties of High-Order Harmonic Beams from Plasma Mirrors: A Ptychographic Study %+ Laboratoire Interactions, Dynamiques et Lasers (ex SPAM) (LIDyl) %+ Lawrence Berkeley National Laboratory [Berkeley] (LBNL) %A Leblanc, A. %A Monchocé, S. %A Vincenti, H. %A Kahaly, S. %A Vay, J.-L. %A Quéré, F. %< avec comité de lecture %@ 0031-9007 %J Physical Review Letters %I American Physical Society %V 119 %P 155001 %8 2017-10 %D 2017 %R 10.1103/PhysRevLett.119.155001 %Z Chemical Sciences/Theoretical and/or physical chemistry %Z Physics [physics]/Mechanics [physics]/Mechanics of materials [physics.class-ph] %Z Physics [physics]/Physics [physics]/Chemical Physics [physics.chem-ph]Journal articles %X Spatial properties of high-order harmonic beams produced by high-intensity laser-matter interactions carry rich information on the physics of the generation process, and their detailed understanding is essential for applications of these light beams. We present a thorough study of these properties in the case of harmonic generation from plasma mirrors, up to the relativistic interaction regime. $In\ situ$ ptychographic measurements of the amplitude and phase spatial profiles of the different harmonic orders in the target plane are presented, as a function of the key interaction parameters. These measurements are used to validate analytical models of the harmonic spatial phase in different generation regimes, and to benchmark ultrahigh-order Maxwell solvers of particle-in-cell simulation codes. %G English %2 https://cea.hal.science/cea-02277333/document %2 https://cea.hal.science/cea-02277333/file/PhysRevLett.119.155001.pdf %L cea-02277333 %U https://cea.hal.science/cea-02277333 %~ CEA %~ CNRS %~ OPENAIRE %~ IRAMIS-LIDYL %~ CEA-UPSAY %~ UNIV-PARIS-SACLAY %~ CEA-UPSAY-SACLAY %~ TEST-HALCNRS %~ ANR %~ GS-ENGINEERING %~ IRAMIS %~ GS-CHIMIE %~ GS-PHYSIQUE %~ INSTITUT-SCIENCES-LUMIERE