TY - JOUR
T1 - Emergence of a Higher Energy Structure in Strong Field Ionization with Inhomogeneous Electric Fields
AU - Ortmann, L.
AU - Pérez-Hernández, J. A.
AU - Ciappina, M. F.
AU - Schötz, J.
AU - Chacón, A.
AU - Zeraouli, G.
AU - Kling, M. F.
AU - Roso, L.
AU - Lewenstein, M.
AU - Landsman, A. S.
N1 - Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/8/4
Y1 - 2017/8/4
N2 - Studies of strong field ionization have historically relied on the strong field approximation, which neglects all spatial dependence in the forces experienced by the electron after ionization. More recently, the small spatial inhomogeneity introduced by the long-range Coulomb potential has been linked to a number of important features in the photoelectron spectrum, such as Coulomb asymmetry, Coulomb focusing, and the low energy structure. Here, we demonstrate using midinfrared laser wavelength that a time-varying spatial dependence in the laser electric field, such as that produced in the vicinity of a nanostructure, creates a prominent higher energy peak. This higher energy structure (HES) originates from direct electrons ionized near the peak of a single half-cycle of the laser pulse. The HES is separated from all other ionization events, with its location and width highly dependent on the strength of spatial inhomogeneity. Hence, the HES can be used as a sensitive tool for near-field characterization in the "intermediate regime," where the electron's quiver amplitude is comparable to the field decay length. Moreover, the large accumulation of electrons with tuneable energy suggests a promising method for creating a localized source of electron pulses of attosecond duration using tabletop laser technology.
AB - Studies of strong field ionization have historically relied on the strong field approximation, which neglects all spatial dependence in the forces experienced by the electron after ionization. More recently, the small spatial inhomogeneity introduced by the long-range Coulomb potential has been linked to a number of important features in the photoelectron spectrum, such as Coulomb asymmetry, Coulomb focusing, and the low energy structure. Here, we demonstrate using midinfrared laser wavelength that a time-varying spatial dependence in the laser electric field, such as that produced in the vicinity of a nanostructure, creates a prominent higher energy peak. This higher energy structure (HES) originates from direct electrons ionized near the peak of a single half-cycle of the laser pulse. The HES is separated from all other ionization events, with its location and width highly dependent on the strength of spatial inhomogeneity. Hence, the HES can be used as a sensitive tool for near-field characterization in the "intermediate regime," where the electron's quiver amplitude is comparable to the field decay length. Moreover, the large accumulation of electrons with tuneable energy suggests a promising method for creating a localized source of electron pulses of attosecond duration using tabletop laser technology.
UR - http://www.scopus.com/inward/record.url?scp=85026871965&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.119.053204
DO - 10.1103/PhysRevLett.119.053204
M3 - 文章
C2 - 28949751
AN - SCOPUS:85026871965
SN - 0031-9007
VL - 119
JO - Physical Review Letters
JF - Physical Review Letters
IS - 5
M1 - 053204
ER -