Time-frequency mapping of two-colour photoemission driven by harmonic radiation. (1st September 2021)

• Record Type: Journal Article
• Authors: Moio, Bruno; Dolso, Gian Luca; Inzani, Giacomo; Di Palo, Nicola; Borrego-Varillas, Rocío; Nisoli, Mauro; Lucchini, Matteo
• Is Part Of: Journal of physics. Volume 54:Number 15(2021)
• Publication Date: 2021-09-01
• Subjects: high-order harmonic radiation -- extreme-ultraviolet -- time-frequency distribution -- two-colour photoemission; Atoms -- Periodicals; Molecules -- Periodicals; Optics -- Periodicals; Nuclear physics -- Periodicals; 539.6
• DOI: 10.1088/1361-6455/ac1ca7
• Languages: English
• ISSNs: 0953-4075

Abstract

Abstract: The use of few-femtosecond, extreme ultraviolet (XUV) pulses, produced by high-order harmonic generation, in combination with few-femtosecond infrared (IR) pulses in pump–probe experiments has great potential to disclose ultrafast dynamics in molecules, nanostructures and solids. A crucial prerequisite is a reliable characterization of the temporal properties of the XUV and IR pulses. Several techniques have been developed. The majority of them applies phase reconstruction algorithms to a photoelectron spectrogram obtained by ionizing an atomic target in a pump–probe fashion. If the ionizing radiation is a single harmonic, all the information is encoded in a two-color two-photon signal called sideband (SB). In this work, we present a simplified model to interpret the time-frequency mapping of the SB signal and we show that the temporal dispersion of the pulses directly maps onto the shape of its spectrogram. Finally, we derive an analytical solution, which allows us to propose a novel procedure to estimate the second-order dispersion of the XUV and IR pulses in real time and with no need for iterative algorithms.