Competition of single and double rescattering in the strong-field photoemission from dielectric nanospheres

Abstract

the carrier-envelope phase-dependent emission of single and double recollision electrons and find that both exhibit a characteristic directional switching behavior. This article is part of the topical collection "Ultrafast Nanooptics" guest edited by Martin Aeschlimann and Walter Pfeiffer.

All-optical spatio-temporal control of electron emission from SiO2 nanospheres with femtosecond two-color laser fields

“…While similar propagation-induced directional control of the electron emission has already been observed with CEP-controlled few-cycle pulses [19,37], those studies have been carried out at a single (central) wavelength, such that a change of the CEP allowed only for control of the up versus down emission, while the directionality could only be steered by changing the particle size. In the present study, we focus on an all-optical control of the emission angle, where in addition to having two distinct fields controlled via the two-color phase, the intensity ratio provides an extra parameter to control the relative strength of propagation induced asymmetry in the electron emission in single-size nanoparticles (shown here for 300 nm).…”

Interplay of pulse duration, peak intensity, and particle size in laser-driven electron emission from silica nanospheres

“…However, when ρ ≥ 1, the dipole distribution begins to break down and higher-order terms significantly contribute, resulting in a shift of the maximum near-field enhancement towards the propagation direction. Previous theoretical work has shown that charge creation and interaction is enhanced in this regime and contributes to the acceleration [24].…”

“…These propagation effects are also referred to as nano-focusing and result in stronger field localization towards the propagation axis and larger field enhancement [34]. explanation might be derived from previous theoretical work, where the contribution of these nonlinear acceleration processes was studied as a function of particle size [24] . It was found that the trapping field contribution (in units of U p ) remains roughly constant, while the Coulomb explosion contribution grows significantly for larger particles due to the stronger confinement of the initial electron bunch.…”

“…We thus tentatively attribute the observed size dependence to the important role of field confinement and stronger repulsion between emitted electrons. A more definite and quantitative explanation of the observed pulse duration dependence, however, requires the challenging extension of the theoretical analysis performed in [24] to longer, multi-cycle pulses.…”

Few-cycle laser driven reaction nanoscopy on aerosolized silica nanoparticles

“…Süßmann et al 14 have revealed that electrons are generated on the nanoparticle surface in the regions of maximum field enhancement and subsequently accelerated in the local near-fields. It has been shown experimentally and theoretically that released electrons gain most of their final energy from a combination of the dielectrically enhanced laser field and a local trapping potential induced by ionization 14,15,28 .…”