"It was fascinating to observe the evolution of the vector-vortex beam during propagation"
This talk addresses the up-conversion of vortex and vector-vortex beams from the infrared into the extreme ultraviolet. The control over spin and orbital angular momentum in high harmonic generation (HHG) enables structuring short-wavelength beams in their polarization and phase [1]. We can imprint high topological charges in twisted wavefronts through HHG, reaching values as high as 100 in a recent Hartmann wavefront characterization [2]. By integrating both a spatially-varying phase and polarization in vector-vortex beams, we reveal novel propagation dynamics in HHG and we build-up attosecond light springs with multiple polarization states that can be oriented in radial or azimuthal configurations.
References [1] A. de las Heras, A. K. Pandey, J. San Román, J. Serrano, E. Baynard, G. Dovillaire, M. Pittman, C. Durfee, L. Plaja, S. Kazamias, O. Guilbaud, and C. Hernández-García, "Extreme-ultraviolet vector-vortex beams from high harmonic generation," Optica, DOI 10.1364/OPTICA.442304 (2021) [2] A. K. Pandey, A. de las Heras, T. Larrieu, J. San Román, J. Serrano, L. Plaja, E. Baynard, G. Dovillaire, M. Pittman, S. Kazamias, C. Hernández-García, and O. Guilbaud, "Characterization of extreme-ultraviolet vortex beams with very high topological charge" (submitted to ACS Photonics).