Customized optical chirality of vortex structured light through state and degree-of-polarization control
Kayn A. Forbes, Dale Green
Abstract
We show how both the ellipticity $\ensuremath{\eta}$ and degree of polarization $P$ influence the extraordinary optical chirality properties of nonparaxial vortex beams. We find that, in stark contrast to paraxial optics and nonvortex modes, extremely rich and tunable spatial distributions of optical chirality density can be produced by an optical vortex beam under tight focusing. We develop a theoretical description of how the optical chirality can be tailored for purpose by altering both the state $\ensuremath{\eta}$ and degree of polarization $P$ of the input vortex mode, along with the magnitude and sign of optical orbital angular momentum via the pseudoscalar topological charge $\ensuremath{\ell}$. We expect that the results will have a significant role in both producing alternative techniques and improving existing methods in chiral nano-optics and structured light photonics.