Bright, single helicity, high harmonics driven by mid-infrared bicircular laser fields.
Opt Express
; 29(23): 38119-38128, 2021 Nov 08.
Article
em En
| MEDLINE
| ID: mdl-34808871
ABSTRACT
High-harmonic generation (HHG) is a unique tabletop light source with femtosecond-to-attosecond pulse duration and tailorable polarization and beam shape. Here, we use counter-rotating femtosecond laser pulses of 0.8 µm and 2.0 µm to extend the photon energy range of circularly polarized high-harmonics and also generate single-helicity HHG spectra. By driving HHG in helium, we produce circularly polarized soft x-ray harmonics beyond 170 eV-the highest photon energy of circularly polarized HHG achieved to date. In an Ar medium, dense spectra at photon energies well beyond the Cooper minimum are generated, with regions composed of a single helicity-consistent with the generation of a train of circularly polarized attosecond pulses. Finally, we show theoretically that circularly polarized HHG photon energies can extend beyond the carbon K edge, extending the range of molecular and materials systems that can be accessed using dynamic HHG chiral spectro-microscopies.
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Base de dados:
MEDLINE
Idioma:
En
Revista:
Opt Express
Assunto da revista:
OFTALMOLOGIA
Ano de publicação:
2021
Tipo de documento:
Article