Generation of Bright and Controllable Isolated Attosecond X-Ray Pulses from Synchronized Mid-Infrared and Ultra-short Ultraviolet Laser Fields

TL;DR

This paper presents a two-color laser scheme combining mid-infrared and ultraviolet pulses to generate bright, isolated, and tunable attosecond X-ray pulses, enhancing tabletop ultrafast spectroscopy and molecular imaging.

Contribution

The study introduces a novel MIR+UV two-color scheme for high-order harmonic generation that improves efficiency and spectral control over traditional single-color methods.

Findings

Enables generation of bright, isolated attosecond X-ray pulses

Provides tunable spectral properties for X-ray pulses

Offers a practical approach compatible with current experimental setups

Abstract

We investigate, by solving the time-dependent Schr\"{o}dinger equation in the single-active-electron approximation in helium, a two-color scheme for tabletop high-order harmonic generation (HHG) that combines a mid-infrared (MIR) driving field with an ultrashort ultraviolet (UV) pulse that could be generated via resonant dispersive wave emission in gas-filled hollow-core fibers. This configuration enables the generation of bright, isolated, and tunable attosecond X-ray pulses. In contrast to single-color driving schemes, which suffer from low conversion efficiency, unfavorable wavelength scaling, and limited spectral control, the MIR+UV approach provides a practical and controllable route for advancing tabletop ultrafast spectroscopy and real-time molecular imaging within current experimental capabilities.