Angle-resolved photoelectron energy spectrum from the high-order above-threshold ionization process in IR+XUV two-color laser fields. (20th November 2018)

• Record Type: Journal Article
• Authors: Jin, Facheng; Li, Fei; Yang, Yujun; Chen, Jing; Liu, Xiaojun; Wang, Bingbing
• Is Part Of: Journal of physics. Volume 51:Number 24(2018:Dec. 28)
• Publication Date: 2018-11-20
• Subjects: high-order above-threshold ionization -- IR+XUV two-color laser fields -- angle-resolved photoelectron energy spectrum -- the frequency-domain theory; Atoms -- Periodicals; Molecules -- Periodicals; Optics -- Periodicals; Nuclear physics -- Periodicals; 539.6
• DOI: 10.1088/1361-6455/aaecdc
• Languages: English
• ISSNs: 0953-4075

Abstract

Abstract: The angle-resolved photoelectron energy spectrum (PES) of high-order above-threshold ionization (HATI) spectrum in IR+XUV two-color laser fields has been investigated. We found that the quantum feature corresponding to the absorption of the XUV photon is well illustrated by a peculiar dip structure in the second plateau of the HATI spectrum. By the channel analysis, we show that the angle-resolved PES is attributed to the coherent summation over contributions of different channels, and the dip structure in the spectrum is directly related to the absorption of one XUV photon of the ionized electron during the laser-assisted collision (LAC) with its parent ion in the two-color laser fields. Moreover, by employing the saddle-point approximation, we obtain the classical energy orbit equation, and find that the dip structure comes from the fact that the LAC is limited at a certain direction by the momentum conservation law as the electron absorbs one XUV photon during the collision, where the probability of the HATI gets its minimum value. Finally, we find that the interference pattern in the whole spectrum is attributed to the interference of different orbits at collision moments t 0 and 2 π / ω 1 − t 0 in the LAC process.