Enhancement of high harmonic generation by confining electron motion in plasmonic nanostrutures

TY - JOUR

T1 - Enhancement of high harmonic generation by confining electron motion in plasmonic nanostrutures

AU - Ciappina, M. F.

AU - Aćimović, Srdjan S.

AU - Shaaran, T.

AU - Biegert, J.

AU - Quidant, R.

AU - Lewenstein, M.

PY - 2012/11/19

Y1 - 2012/11/19

N2 - We study high-order harmonic generation (HHG) resulting from the illumination of plasmonic nanostructures with a short laser pulse of long wavelength. We demonstrate that both the confinement of the electron motion and the inhomogeneous character of the laser electric field play an important role in the HHG process and lead to a significant increase of the harmonic cutoff. In particular, in bow-tie nanostructures with small gaps, electron trajectories with large excursion amplitudes experience significant confinement and their contribution is essentially suppressed. In order to understand and characterize this feature, we combine the numerical solution of the time-dependent Schrödinger equation (TDSE) with the electric fields obtained from 3D finite element simulations. We employ time-frequency analysis to extract more detailed information from the TDSE results and classical tools to explain the extended harmonic spectra. The spatial inhomogeneity of the laser electric field modifies substantially the electron trajectories and contributes also to cutoff increase.

AB - We study high-order harmonic generation (HHG) resulting from the illumination of plasmonic nanostructures with a short laser pulse of long wavelength. We demonstrate that both the confinement of the electron motion and the inhomogeneous character of the laser electric field play an important role in the HHG process and lead to a significant increase of the harmonic cutoff. In particular, in bow-tie nanostructures with small gaps, electron trajectories with large excursion amplitudes experience significant confinement and their contribution is essentially suppressed. In order to understand and characterize this feature, we combine the numerical solution of the time-dependent Schrödinger equation (TDSE) with the electric fields obtained from 3D finite element simulations. We employ time-frequency analysis to extract more detailed information from the TDSE results and classical tools to explain the extended harmonic spectra. The spatial inhomogeneity of the laser electric field modifies substantially the electron trajectories and contributes also to cutoff increase.

UR - http://www.scopus.com/inward/record.url?scp=84870580929&partnerID=8YFLogxK

U2 - 10.1364/OE.20.026261

DO - 10.1364/OE.20.026261

M3 - 文章

C2 - 23187480

AN - SCOPUS:84870580929

SN - 1094-4087

VL - 20

SP - 26261

EP - 26274

JO - Optics Express

JF - Optics Express

IS - 24

ER -