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We report on free-space strategy for electromagnetic concealment of three-dimensional macroscopic objects in the optical domain owing to unique energy flow redirection capabilities enabled by optical phase singularities. We propose and implement the generation of a quasi-nodal volume based on optical vortex Fourier processing, which inhibits light scattering from objects placed inside. The proof of concept is made by numerical simulations and the experimental implementation is carried out in the visible domain by using geometric phase vortex phase masks. Optical cloaking demonstration is made by using stainless steel sphere as the object to be concealed. The geometric phase nature of the vortex masks confers polarization independent features to the device and makes it possible to implement in a reflection mode.

Light transmission through and reflection from a medium layer with dielectric and magnetic helicities are discussed. The axes of the dielectric permittivity tensor, , and the magnetic permeability tensor, , as well as the medium helix axis are all parallel to each other and they are perpendicular to the boundary surfaces. The possibilities of formation of some new types of photonic bandgaps (PBGs) are presented for large anisotropies of the medium?namely, direct and indirect nonselective PBGs (with respect to the incident light polarization, in contrast to the usual direct PBGs, which are selective with respect to the polarization of the incident light). It is shown that a transmission region can arise among the three types of PBGs, in certain conditions, of course. In this paper we generalize the concept of nihility for structurally chiral media, such as cholesteric liquid crystals (CLCs) and we identify two types of CLC nihilities. It is shown that, for certain characteristic parameters of the medium, superluminal light propagation is possible in the transmission band. The influence of the anisotropy of the medium on the reflection spectra is considered and it is shown that one can tune the width, number and frequency range of PBGs of this layer, at essentially large limits, tuning the parameters of the layer. The case of oblique light incidence on the CLC layer is also discussed.