Attosecond-XUV pulse generation using laser-based high-harmonic generation in argon gas

High harmonic cut-off in high harmonic generation (HHG) based photon source is limited which restricts its further applications. In this work, we study single laser and three optical lasers based HHG in argon gas and analyze the harmonic cut-off of HHG spectra and the generated photon pulse structure. It is observed that the high harmonic spectrum strongly depends on the laser parameters such as wavelength, pulse duration, laser intensities. An extreme-ultraviolet (XUV) photon pulse of 90 keV photon energy with 270 as FWHM photon pulse duration is demonstrated in single laser-based HHG. However, in three colour laser case, it is extended up to 273 eV with 131 as FWHM photon pulse duration. Effect of time delays in-between the lasers is also studied on HHG spectrum and on the generated photon pulse characteristics. Effect of carrier-envelope phase (CEP) of laser is also discussed on photon pulse characteristics. Generation of such XUV-attosecond photon pulse is extremely important for the study of ultrafast dynamics in atoms and molecules.

Automated summary

This study investigates the characteristics of high harmonic generation (HHG) in argon gas using single laser and three optical lasers. It analyzes the harmonic cut-off of HHG spectra and the generated photon pulse structure. The results show that the laser parameters, such as wavelength, pulse duration, and laser intensity, strongly influence the high harmonic spectrum. Single laser-based HHG can generate an XUV photon pulse with a photon energy of 90 keV and a pulse duration of 270 as FWHM, while three colour laser-based HHG can extend it to 273 eV with a pulse duration of 131 as FWHM. The effects of time delays between the lasers and the carrier-envelope phase (CEP) of the laser on photon pulse characteristics are also discussed.