title: Arbitrary, direct and deterministic manipulation of vector beams via electrically-tuned q-plates.
abstract: Vectorial vortex light beams, also referred to as spirally polarized beams, are of particular interest since they can be exploited in several applications ranging from quantum communication to spectroscopy and microscopy. In particular, symmetric pairs of vector beams define two-dimensional spaces which are described as "hybrid Poincaré spheres" (HPS). While generation of vortex beams has been demonstrated by various techniques, their manipulation, in particular in order to obtain transformations describing curves entirely contained on a given HPS, is quite challenging, as it requires a simultaneous action on both polarization and orbital angular momentum degrees of freedom. Here, we demonstrate experimentally this kind of manipulation by exploiting electrically-tuned q-plates: an arbitrary transformation on the HPS can be obtained, by controlling two parameters of the q-plate, namely the initial optic axis orientation α0 and the uniform birefringent phase retardation δ. Upon varying such parameters, one can determine both the rotation axis and the rotation angle on the HPS, obtaining the desired state manipulation with high fidelity.
authors.affiliation: Dipartimento di Fisica, "Sapienza" Università di Roma, I-00185 Roma, Italy.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: D'Ambrosio
authors.affiliation: Dipartimento di Fisica, "Sapienza" Università di Roma, I-00185 Roma, Italy.
authors.forename: Flavio
authors.initials: F
authors.lastname: Baccari
authors.affiliation: 1] Dipartimento di Fisica, Università di Napoli Federico II, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy [2] Centre for Quantum Dynamics and Centre for Quantum Computation and Communication Technology, Griffith University, Brisbane, Queensland 4111, Australia.
authors.forename: Sergei
authors.initials: S
authors.lastname: Slussarenko
authors.affiliation: 1] Dipartimento di Fisica, Università di Napoli Federico II, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy [2] CNR-SPIN, Complesso Universitario di Monte S. Angelo, 80126 Napoli, Italy.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Marrucci
authors.affiliation: Dipartimento di Fisica, "Sapienza" Università di Roma, I-00185 Roma, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Sciarrino