We present a hybrid Poincaré sphere, whose eigenstates are defined as a pair of circularly polarized fundamental-mode Gaussian beam and a Laguerre-Gaussian beam, to describe the so-called full Poincaré beam. We also show that any desired full Poincaré beam over the hybrid Poincaré sphere via modulating the incident polarization state of light and two cascaded half-wave plates. This research provides an alternative way for charactering and manipulating the full Poincaré beam and an effective method to control the polarization state of light.
In this work, we present a method for generating vector vortex beams with metasurfaces. A Jones calculation is employed to theoretically analyze the phase and polarization transformation from metasurfaces. The experimental results are shown to agree well with our theoretical calculation. Lastly, as a geometrical representation, the hybrid-order Poincaré sphere is proposed to describe the evolution of polarization state and phase of light wave propagating in metasurfaces. The hybrid-order Poincaré sphere can intuitively demonstrate the change of polarization state and. So it can also become an effective tool to provide help in designing metasurfaces.
We report the demonstration of intrinsic spin Hall effect (SHE) of cylindrical vector beam. Employing a fan-shaped aperture to block part of the vector beam, the intrinsic vortex phases are no longer continuous in the azimuthal direction, and results in the spin accumulation at the opposite edges of the light beam. Due to the inherent nature of the phase and independency of light-matter interaction, the observed SHE is intrinsic. Modulating the topological charge of the vector beam, the spin-dependent splitting can be enhanced and the direction of spin accumulation is switchable.
Observation of photonic spin Hall effect (SHE) manifested by spin-dependent splitting of light in a dielectric-based birefringent metasurface is reported experimentally. By designing the metasurface with homogeneous phase retardation but space-variant optical axis directions, we govern the photonic SHE via space-variant Pancharatnam-Berry phase originated from the local polarization manipulation of the metasurface, essentially, the spin-orbit interaction between the light and the metasurface. Modulating the polarization distribution of the incident light and/or the structure geometry of the metasurface, the photonic SHE could be tunable. This type of metasurface offers an effective way to manipulate the spin-polarized photons and a route for spin-controlled nanophotonic applications.