Twisting attosecond pulse trains by amplitude-polarization IR pulses

ENRIQUE G. NEYRA; DEMIAN A. BIASETTI; FABIÁN VIDELA; MARCELO CIAPPINA; LORENA REBÓN

PHYSICAL REVIEW A - ATOMIC, MOLECULAR AND OPTICAL PHYSICS

AMER PHYSICAL SOC

Lugar: New York; Año: 2023

1050-2947

Natively, atomic and molecular processes develop in a sub-femtosecond time scale. In order to, forinstance, track and capture the electron motion in that scale we need suitable ‘probes’. Attosecondpulses configure the most appropriate tools for such a purpose. These ultrashort bursts of lightare generated when a strong laser field interacts with matter and high-order harmonics of thedriving source are produced. In this work, we propose a way to twist attosecond pulse trains. Inour scheme, each of the attosecond pulses in the train has a well-defined linear polarization, butwith a different polarization angle between them. To achieve this goal, we consider an infraredpulse with a particular polarization state, called amplitude polarization. This kind of pulse wasexperimentally synthesized in previous works. Our twisted attosecond pulse train is then obtainedby nonlinear driving an atomic system with that laser source, through the high-order harmonicsgeneration phenomenon. We achieve a considerable level of control over the modulation of thelinear polarization state between two consecutive ultrashort bursts of XUV radiation. Throughquantum mechanical simulations, supplemented with signal processing tools, we are able to dissect the underlying physics of the generation process. We are confident these polarized-sculpted XUV sources will play an instrumental role in future pump-probe-based experiments.