Spatially and spectrally resolved quantum path interference with chirped driving pulses. (23rd December 2016)

• Record Type: Journal Article
• Authors: Carlström, Stefanos; Preclíková, Jana; Lorek, Eleonora; Larsen, Esben Witting; Heyl, Christoph M; Paleček, David; Zigmantas, Donatas; Schafer, Kenneth J; Gaarde, Mette B; Mauritsson, Johan
• Is Part Of: New journal of physics. Volume 18:Number 12(2016:Dec.)
• Publication Date: 2016-12-23
• Subjects: high-order harmonic generation -- quantum path interference -- dipole phase parameters; 42.65.Ky -- 42.65.Re; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/aa511f
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: We measure spectrally and spatially resolved high-order harmonics generated in argon using chirped multi-cycle laser pulses. Using a stable, high-repetition rate laser we observe detailed interference structures in the far-field. The structures are of two kinds; off-axis interference from the long trajectory only and on-axis interference including the short and long trajectories. The former is readily visible in the far-field spectrum, modulating both the spectral and spatial profile. To access the latter, we vary the chirp of the fundamental, imparting different phases on the different trajectories, thereby changing their relative phase. Using this method together with an analytical model, we are able to explain the on-axis behaviour and access the dipole phase parameters for the short ( α s ) and long ( α l ) trajectories. The extracted results compare very well with phase parameters calculated by solving the time-dependent Schrödinger equation. Going beyond the analytical model, we are also able to successfully reproduce the off-axis interference structure.