SKM 2023 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

HL: Fachverband Halbleiterphysik

HL 17: THz and MIR physics in semiconductors

HL 17.2: Vortrag

Dienstag, 28. März 2023, 09:45–10:00, JAN 0027

Generation of THz vortex beams and interferometric determination of their topological charge — •Samuel W. Pinnock, Seulki Roh, Tobias Biesner, Artem V. Pronin, and Martin Dressel — 1. Physikalisches Institut, Universität Stuttgart, 70569 Stuttgart, Germany

We developed and demonstrated the efficacy of 3D printed spiral phase plates for the generation of vortex THz beams with orbital angular momenta ℓ = ± 1 and ℓ = ± 2. The vortex beam generation was confirmed by means of frequency-domain transmission spectroscopy. The topological charge of the vortex beams was determined via phase-sensitive Mach-Zehnder interferometry, which enabled the superposition of a vortex beam with ℓ and its conjugate beam with −ℓ. The resulting interference patterns were found to be consistent with the expected intensity distributions for a given ℓ, which provides strong confirmation of the spatial phase structure of the generated vortex beams in the THz regime. Such THz vortex beams could be used in spectroscopic studies of optical transitions with Δ ℓ ≠ 0 in different condensed-matter systems, including semiconductors and topological materials.