Circularly polarized high harmonic beams carrying self-torque or time-dependent orbital angular momentum

• DOI: 10.48550/arxiv.2407.20707
• Publication Date: 2024-07-30
• Authors: Alba de las Heras; Julio San Román; Javier Serrano; Luis Plaja; Carlos Hernández-...
• Keywords: Harmonic; Azimuthal quantum number

In the rapidly evolving field of structured light, self-torque has been recently defined as an intrinsic property light beams carrying time-dependent orbital angular momentum. particular, extreme-ultraviolet (EUV) with -- exhibiting a topological charge that continuously varies on subfemtosecond timescale are naturally produced in high-order harmonic generation (HHG) when driven by two time-delayed intense infrared vortex different charges. Until now, polarization state such EUV restricted to linear states due drastic reduction up-conversion efficiency increasing ellipticity driving field. this work, we theoretically demonstrate how control self-torque, from circular. The extremely high sensitivity HHG properties beam allows us propose schemes circumvent current limitations manipulate self-torque. Our advanced numerical simulations complemented derivation selection rules momentum conservation, which enable precise tunability over harmonics resulting emission, custom state, can expand applications ultrafast light-matter interactions, particularly areas where dichroic or chiral crucial, magnetic materials molecules.