High-order vortex harmonic generation with circular Airy vortex beams

High-order harmonic generation (HHG) driven by an abruptly autofocusing circular Airy vortex beam (CAiVB) is investigated here. The autofocusing property of the CAiVB gives HHG a low initial intensity. The slow divergence after focusing provides a long and sufficiently intense region, which is favorable for HHG. Here, we analyze the phase-matching mechanism in detail by plotting the spatial diagram of the coherence length, while simulating HHG driven by the CAiVB carrying distinct orbital angular momentum in a gas medium, as well as the harmonic distributions in the near and far fields.(c) 2023 Optica Publishing Group