Intense vortex high-order harmonics generated from laser-ablated plume

Abstract

In this study, we demonstrate intense extreme-ultraviolet optical vortices generated using laserablation plume as the nonlinear medium. We used two types of plumes that are known to generate intense high-order harmonics for driving lasers with Gaussian beam profiles, but through different mechanisms, namely carbon (diatomic carbon molecules) and tin (resonance with autoionizing state). We find that the harmonic fluxes for diatomic carbon molecules are similar for Gaussian and vortex driving fields. However, for harmonics from the autoionizing state of tin (~26.3 eV), the enhancement factor of the resonant harmonic intensity decreases by ~50% when using the vortex driving field. The intense extreme-ultraviolet optical vortices demonstrated in this study will be useful for many applications including a new material characterization technique known as optical angular momentum dichroism as well as the spectroscopy of spin-forbidden electronic transitions.

Generation of Complex Vector and Vortex Extreme Ultraviolet Beams Using the S-Waveplate and Spiral Phase Plate during High-Order Harmonics Generation in Argon

“…The generation of intense high-order harmonics during the propagation of polarization-structured vector beams (radially polarized beams, azimuthally polarized beams, and their superpositions) through laser-induced plasmas (C, Sn, In, CdS, ZnS, Ag 2 S) was reported in refs and . HHG yield using the radially and azimuthally polarized beams was ∼1.5 to 2 times stronger than that using the linearly polarized beams.…”

Spatial and spectral variations of high-order harmonics generated in noble gases

“…The influence of the beam shape on the spectral distribution of the HHG has been analyzed in earlier studies [15]. Generation of intense XUV optical vortices in laser-ablation plumes has been also reported by Singh et al [16]. Resonanceenhanced HHG in the field of structured Gaussian driving pulses (DPs) has been demonstrated.…”

High-Order Harmonics Generation in MoS2 Transition Metal Dichalcogenides: Effect of Nickel and Carbon Nanotube Dopants

“…Hence, to increase the yield and cut-off energy of harmonics, different schemes like resonance-induced enhancement, quasi-phase matching of harmonics, application of multi-particle species, optimization of laser parameters, use of polarization structured beams, multicolor excitation, etc. have been introduced [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ].…”