Space- and time-resolved observation of extreme laser frequency upshifting during ultrafast-ionization
Authors: Giulietti A., André A., Dufrénoy D.S., Giulietti D., Hosokai T., Koester P., Kotaki H., Labate L., Levato T., Nuter R., Pathak N.C., Monot P., Gizzi LA.
Autors Affiliation: Intense Laser Irradiation Laboratory, Istituto Nazionale di Ottica, CNR Campus, Via Moruzzi, 1, 56124 Pisa, Italy; CEA-Saclay DSM-IRAMIS-SPAM, 91191 Gif sur Yvette, France; Dipartimento di Fisica, Università di Pisa, Pisa, Italy; Istituto Nazionale di Fisica Nucleare, Pisa, Italy; Photon Pioneer Center, Osaka University, Osaka, Japan; Japan Atomic Energy Agency (JAEA), Kizugawa, Kyoto, Japa;n CEA-Arpajon DIF-DAM, Arpajon, France
Abstract: A 65-fs, 800-nm, 2-TW laser pulse propagating through a nitrogen gas jet has been experimentally studied by 90 degrees Thomson scattering. Time-integrated spectra of scattered light show unprecedented broadening towards the blue which exceeds 300 nm. Images of the scattering region provide for the first time a space-and time-resolved description of the process leading quite regularly to such a large upshift. The mean shifting rate was as high as delta lambda/delta t approximate to 3 angstrom/fs, never observed before. Interferometry shows that it occurs after partial laser defocusing. Numerical simulations prove that such an upshift is consistent with a laser-gas late interaction, when laser intensity has decreased well below relativistic values (a(0) << 1) and ionization process involves most of the laser pulse. This kind of interaction makes spectral tuning of ultrashort intense laser pulses possible in a large spectral range. (C) 2013 AIP Publishing LLC. Journal/Review: PHYSICS OF PLASMAS
Volume: 20 (8) Pages from: 082307 to: 082307
More Information: This work was supported by the \”ELI Italy\” funded by CNR and by the gamma-RESIST project funded by INFN. Simulation with CALDER code was with HPC resources from GENCI-CCRT/CINES (Grant No. 2011-056067). Deep gratitude is due to Ph. Martin and F. Quere for enlightening discussions. The authors would like to thank also C. A. Cecchetti for his contribution, W. Baldeschi, A. Barbini, F. Pardini, A. Rossi, and M. Voliani for their technical support. A. G. is grateful to Federica Baffigi for her help in revising the manuscript.DOI: 10.1063/1.4818602Citations: 7data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2022-01-16References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here