Abstract
The optical chirality and spin angular momentum of structured scalar vortex beams has been intensively studied in recent years. The pseudoscalar topological charge ℓ of these beams is responsible for their unique properties. Constructed from a superposition of scalar vortex beams with topological charges ℓ A and ℓ B , cylindrical vector vortex beams are higher-order Poincaré modes which possess a spatially inhomogeneous polarization distribution. Here we highlight the highly tailorable and exotic spatial distributions of the optical spin and chirality densities of these higher-order structured beams under both paraxial (weak focusing) and non-paraxial (tight focusing) conditions. Our analytical theory can yield the spin angular momentum and optical chirality of each point on any higher-order or hybrid-order Poincaré sphere. It is shown that the tunable Pancharatnam topological charge ℓ P = ( ℓ A + ℓ B ) / 2 and polarization index m = ( ℓ B − ℓ A ) / 2 of the vector vortex beam plays a decisive role in customizing their spin and chirality spatial distributions. We also provide the correct analytical equations to describe a focused, non-paraxial scalar Bessel beam.
Original language | English |
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Article number | 125401 |
Number of pages | 14 |
Journal | Journal of Optics |
Volume | 26 |
Issue number | 12 |
DOIs | |
Publication status | Published - 8 Nov 2024 |
Keywords
- nano optics
- nonparaxial
- optical angular momentum
- optical chirality
- optical vortex
- structured light
- vector beams