High-order harmonic generation from ions in a capillary discharge.
We demonstrate a significant extension of the high-order harmonic cutoff by using a fully-ionized capillary discharge plasma as the generation medium. The preionized plasma dramatically reduces ionization-induced defocusing and energy loss of the driving laser due to ionization. This allows for significantly higher photon energies, up to 150 eV, to be generated from xenon ions, compared with the 70 eV observed previously. We also demonstrate enhancement of the harmonic flux of nearly 2 orders of magnitude at photon energies around 90 eV when the capillary discharge is used to ionize xenon, compared with harmonic generation in a hollow waveguide. The use of a plasma as a medium for high-order harmonic generation shows great promise for extending efficient harmonic generation to much shorter wavelengths using ions.
Gaudiosi
David M
DM
JILA, University of Colorado and National Institute of Standards and Technology, 440 UCB, Boulder, Colorado, 80309-0440, USA.
Reagan
Brendan
B
Popmintchev
Tenio
T
Grisham
Michael
M
Berrill
Mark
M
Cohen
Oren
O
Walker
Barry C
BC
Murnane
Margaret M
MM
Kapteyn
Henry C
HC
Rocca
Jorge J
JJ