% IMPORTANT: The following is UTF-8 encoded.  This means that in the presence
% of non-ASCII characters, it will not work with BibTeX 0.99 or older.
% Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or
% “biber”.

@ARTICLE{Azzolin:640318,
      author       = {Azzolin, Agata and Giovannetti, Gaia and Cannelli, Oliviero
                      and Guangyu, Fan and Ahsan, Md Sabbir and Colaizzi, Lorenzo
                      and Maansson, Erik and Tettenborn, Noah and Oberti, Linda
                      and Facciala, Davide and Frassetto, Fabio and Ciriolo, Anna
                      Grabriella and Lodi, Dario W. and Ashraf, Alia and Manzoni,
                      Christian and Martínez Vázquez, Rebeca and Devetta,
                      Michele and Osellame, Roberto and poletto, luca and Stagira,
                      Salvatore and Vozzi, Caterina and Mullins, Terence and
                      Wanie, Vincent and Trabattoni, Andrea and Calegari,
                      Francesca},
      title        = {{E}ngineering {H}igh-{O}rder {H}armonic {G}eneration
                      through {G}as {C}onfinement at {S}ub-{M}illimeter {L}engths},
      journal      = {JPhys photonics},
      volume       = {8},
      number       = {1},
      issn         = {2515-7647},
      address      = {Bristol},
      publisher    = {IOP Publishing},
      reportid     = {PUBDB-2025-04769},
      pages        = {015057},
      year         = {2025},
      abstract     = {Attosecond light sources based on high-order harmonic
                      generation (HHG) constitute to date the only table-top
                      solution for producing coherent broadband radiation covering
                      the spectral range from the extreme ultraviolet to the soft
                      X-rays. The so-called emission cutoff can be extended
                      towards higher photon energies by increasing the driving
                      wavelength at the expense of conversion efficiency. An
                      alternative route is to overdrive the process by using
                      higher laser intensities, with the challenging requirement
                      of interacting with higher plasma densities over short
                      propagation distances. Here, we address this challenge by
                      using a differentially pumped glass chip designed for
                      optimal gas confinement over sub-mm lengths. By driving HHG
                      with multicycle pulses at either 800 nm or 1500 nm, we
                      demonstrate a cutoff extension by a factor of two compared
                      to conventional phase matching approaches and surpassing the
                      present record using multicycle fields. Our
                      three-dimensional propagation simulations, in excellent
                      agreement with the experiment, confirm that gas confinement
                      is crucial since efficient phase matching of cutoff
                      harmonics occurs only for short propagation lengths.
                      Additionally, we show that the high photon energy component
                      is not only temporally confined to the leading edge of the
                      driving pulse, but also spatially confined in the near-field
                      to an off-axis contribution due to reshaping of the driving
                      field along propagation inside the medium. Our findings
                      contribute to the fundamental understanding of HHG across
                      different regimes.},
      cin          = {FS-ATTO},
      ddc          = {530},
      cid          = {I:(DE-H253)FS-ATTO-20170403},
      pnm          = {631 - Matter – Dynamics, Mechanisms and Control
                      (POF4-631) / DFG project G:(GEPRIS)390715994 - EXC 2056:
                      CUI: Tiefe Einblicke in Materie (390715994) / METRICS -
                      Element-selective impulsive electronic and vibrational
                      spectroscopy of iron-sulfur clusters (101106352) / DFG
                      project G:(GEPRIS)545611997 - Vermessung von chiralen
                      Transienten von Attosekunden bis Femtosekunden durch
                      ultraschnelle Spektroskopie (545611997) / SoftMeter -
                      Multi-messenger soft-field spectroscopy of molecular
                      electronics at interfaces (101076500)},
      pid          = {G:(DE-HGF)POF4-631 / G:(GEPRIS)390715994 /
                      G:(EU-Grant)101106352 / G:(GEPRIS)545611997 /
                      G:(EU-Grant)101076500},
      experiment   = {EXP:(DE-MLZ)NOSPEC-20140101},
      typ          = {PUB:(DE-HGF)16},
      doi          = {10.1088/2515-7647/ae4080},
      url          = {https://bib-pubdb1.desy.de/record/640318},
}