Controlling high harmonic generation using inhomogeneous two-color driving laser pulse

Abstract

High harmonic generation (HHG) is strongly modified near plasmonic nanostructures due to confinement and inhomogeneity of the electromagnetic field. Previous studies have revealed low-intensity generation of HHG and extension of the plateau; however, the roles of potential shape and a combination of inhomogeneous infrared (IR) and blue fields on HHG have not been studied. In this work, we study HHG driven by inhomogeneous two-color (800–400 nm) IR and blue femtosecond pulses by numerically solving the time-dependent Schrödinger equation. HHG spectra are computed for two different models: for a short-range potential, which supports a single-bound state, and for a long-range potential, which supports a Rydberg series, to show potential dependence on inhomogeneous two-color HHG. A substantial enhancement in the value of the cut-off resulting from inhomogeneity up to the ∼600th order, extending beyond the water window, is found for both the models. The HHG spectra are highly sensitive to the relative phase of the two-color fields and this sensitivity increases with increasing inhomogeneity. Possibilities of efficiently generating and controlling attosecond pulse train and isolated attosecond pulse are discussed.

Control of quantum paths in harmonic generation through orthogonal fields specific frequency ratios

“…In additionThe photoelectron momentum distributions of the N 2 molecule depends on the orientation of the molecule, providing an aid in probing the interior of the molecule with ultrafast electron dynamics [17]. To generate supercontinuum high-order harmonics and synthesize isolated attosecond pulses, various schemes have been proposed, including few-cycle laser pulses [18][19][20], two-color fields [21][22][23], and polarization gating [24][25][26].…”

High harmonic generation near a bow-tie nanostructure: sensitivity to carrier envelope phase and plasmonic inhomogeneity

“…The control of HHG spectra and subsequent production of the XUV pulses using various shaping of driving in the presence of plasmonic nanostructure are demonstrated recently. For example, highly efficient supercontinuum generation near plasmonic nanostructure is shown using ultraviolet (UV)/infrared (IR) assisted IR pulses [19][20][21][22]. Simultaneous extension and enhancement of cutoff is observed through UV-assisted IR laser fields [23].…”