Angle-resolved photoelectron spectra in laser-assisted photoionization

GRAMAJO, A A; DELLA PICCA, R; LOPEZ, SEBASTIÁN; ARBÓ, D G

Workshop; PALM International School 2018 - Attosecond Science: from ultrafast sources to applications; 2018

In laser-assisted XUV photoemission (LAPE), the XUV and optical laser overlap in space and time. When the XUV pulse is longer than the laser period, a photoelectron is emitted into the optical dressing field where one or more quanta of energy can be absorbed and emitted. As a result, the photoelectron spectrum shows sidebands (SBs) separated in energy whose intensity depends on the XUV photon energy and dressing field strength [1]. In this work, making use of a semiclassical model (SCM) [2, 3], we describe the angle-resolved photoelectron spectra for the case that both fields are linearly polarized in the same direction. We thoroughly analyze and characterize two different emission regions in the angle-energy domain: the parallel-like and the perpendicular-like regions. As result, we have an interference problem in the time domain which involves two different contributions: (i) the intracycle interference stemming from trajectories within the same cycle, which has a richer structure in the perpendicular-like region (four contributing electron trajectories) than in the parallel-like region (two contributing trajectories), and (ii) the intercycle interference stemming from trajectories released at different cycles, resulting in the well-known SBs.