title: Geometric phase shaping of terahertz vortex beams.
abstract: We propose a topological beam-shaping strategy of terahertz (THz) beams using geometric phase elements made of space-variant birefringent slabs. Quasi-monochromatic THz vortex beams are produced and characterized both in amplitude and phase from the reconstructed real-time two-dimensional imaging of the electric field. Nonseparable superpositions of such vortex beams are also obtained and characterized by two-dimensional polarimetric analysis. These results emphasize the versatility of the spin-orbit electromagnetic toolbox to prepare on-demand structured light endowed with polarization-controlled orbital angular momentum content in the THz domain, which should find many uses in future THz technologies.
authors.forename: Amalya
authors.initials: A
authors.lastname: Minasyan
authors.forename: Clément
authors.initials: C
authors.lastname: Trovato
authors.forename: Jérôme
authors.initials: J
authors.lastname: Degert
authors.forename: Eric
authors.initials: E
authors.lastname: Freysz
authors.forename: Etienne
authors.initials: E
authors.lastname: Brasselet
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Abraham