High-order harmonic emission in bowtie-shaped nanostructure with few-cycle spatially inhomogeneous laser fields when the atom is placed at different spatial positions
Abstract
In this study, we investigate the harmonic spectra in the vicinity of the center of the nanostructure gap when helium atom is placed at different spatial positions. We find that the high-order harmonic spectra is very sensitive to the atomic spatial positions in a inhomogeneous laser field. When the initial atomic spatial position is changed from -9.0 a.u. to 9.0 a.u., the cutoff of the high-order harmonic generation (HHG) can be extended, and the supercontinuum harmonic spectrum of the second plateau is extended to the high-order and the low-order simultaneously. The HHG process is demonstrated by using the time-frequency analysis, the semi-classical three-step model and the ionization probability.
- Publication:
-
Laser Physics
- Pub Date:
- November 2016
- DOI:
- 10.1088/1054-660X/26/11/115301
- Bibcode:
- 2016LaPhy..26k5301L