Targeting multiple rescatterings through VUV-controlled high-order-harmonic generation

Abstract

We theoretically investigate the use of an isolated attosecond vacuum ultraviolet (VUV) pulse to control the emergence of multiple wavepacket rescatterings in the process of high harmonic generation (HHG). Through numerical solution of the time-dependent Schrödinger equation for a helium atom driven by 0.8 − 2.0 µm light, we establish the relationship between evidence of multiple rescatterings in HHG and the time delay between the VUV and infrared pulses. We find features of multiple rescatterings present in both the time and frequency domains of emitted HHG, and demonstrate the use of VUV-induced multiple rescatterings for generating trains of ultrashort light pulses.

Exploration of laser-driven electron-multirescattering dynamics in high-order harmonic generation

“…This supercontinuum harmonic generation supports an isolated 45 as pulse with a bandwidth of 124 eV by superposing the HHG from the 160 th to the 360 th order harmonics. According to the previous study 12 , the HHG can be extended to the keV energies in an ultra-strong mid-infrared laser field, while the HHG with the keV energies can be optimized by controlling of the multiple rescattering 16 .…”

“…Miller et al . 16 have theoretically studied the control of the emergence of multiple wave-packet rescattering in the process of HHG by using an isolated attosecond vacuum ultraviolet pulse. Tong et al .…”

Perfect absorption in Schrödinger-like problems using non-equidistant complex grids

“…This original formulation of irECS was given in terms of a finite element discretization. To our knowledge (and surprise) irECS has not been implemented by other practitioners, although its good performance appears to have lead to a re-assessment of ECS methods for absorption and encouraging results were reported [4][5][6][7].…”

“…In spite of being "perfect" and, as we will demonstrate below, also highly efficient, ECS has remained the least popular of the three methods, although we may be observing a recent surge in its application [4][5][6][7]. The rare use may be related to the fact the ECS requires more care in the implementation than CAP and MFA.…”

High-harmonic spectroscopy of laser-driven nonadiabatic electron dynamics in the hydrogen molecular ion

“…Attosecond temporal resolution of electron dynamics can be achieved via high harmonic generation (HHG) through the interaction of atoms and molecules with intense femtosecond lasers [2]. It involves the release of an electron wavepacket into the continuum through tunneling, followed by its laser-driven propagation away from and then back towards the parent ion [3][4][5]; upon recombination, HHG with photon energies extending to the soft-X-ray region [6] is generated. Each of the three steps (emission, propagation and recombination) occurs on a femto-or sub-femtosecond time span.…”