Classical effect for enhanced high harmonic yield in ultrashort laser pulses with a moderate laser intensity. (28th February 2017)

• Record Type: Journal Article
• Authors: Shi, Y Z; Wang, S; Dong, F L; Li, Y P; Chen, Y J
• Is Part Of: Journal of physics. Volume 50:Number 6(2017:Mar. 15)
• Publication Date: 2017-02-28
• Subjects: ultrashort laser pulse -- harmonic spectrum -- HHG yield; 33.20.Xx; Atoms -- Periodicals; Molecules -- Periodicals; Optics -- Periodicals; Nuclear physics -- Periodicals; 539.6
• DOI: 10.1088/1361-6455/50/6/065004
• Languages: English
• ISSNs: 0953-4075

Abstract

Abstract: We study the influence of pulse duration on high harmonic generation (HHG) by exploring a wide laser-parameter region theoretically. Previous studies have shown that for high laser intensities close to saturation ionization intensity, the HHG inversion efficiency is higher for shorter pulses since the ground-state depletion is weaker in short pulses. Our simulations show that this high efficiency also appears for a moderate laser intensity at which the ionization is not very strong. A classical effect relating to shorter travel distances of the rescattering electron in shorter pulses is shown to contribute importantly to this high efficiency. The effect can be amplified significantly if a two-color laser field is used, suggesting a potential approach to increasing the HHG yield and generating short and bright attosecond pulses.