Manipulation of the Photonic Spin Hall Effect with High Efficiency in Gold-Nanorod-Based Metasurfaces

The photonic spin Hall effect (PSHE) has attracted great interest of the scientific community because of the wide range of spin-controlled nanophotonics applications that it can provide. However, the PSHE is very weak in the reflection and refraction at an interface because of the extremely small spin-orbit interaction. Here, a significant photonic spin Hall effect is reported exhibiting over 70% efficiency in refraction by a gold-nanorod-based metasurface. Moreover, the spin-dependent wave-vector and beam-centroid shifts of the converted refracted waves can be manipulated effectively by changing the periodic length of the proposed metasurface and the transmission distance, respectively. The results suggest intriguing possibilities for manipulating photon spins and orbital angular momentum for applications in nanophotonics and optical communications.