TY - JOUR
KW - Atomic and Molecular Physics, and Optics
AU - Kevin Dorney
AU - Tingting Fan
AU - Quynh Nguyen
AU - Jennifer Ellis
AU - Daniel Hickstein
AU - Nathan Brooks
AU - Dmitriy Zusin
AU - Christian Gentry
AU - Carlos Hernández-García
AU - Henry Kapteyn
AU - Margaret Murnane
AB - 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.

© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
BT - Optics Express
DA - 2021-11
DO - 10.1364/oe.440813
IS - 23
N2 - 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.

© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
PB - The Optical Society
PY - 2021
EP - 38119
T2 - Optics Express
TI - Bright, single helicity, high harmonics driven by mid-infrared bicircular laser fields
VL - 29
SN - 1094-4087
ER -