Tunable spin splitting of reflected Laguerre-Gaussian beams on controllable metamaterials with anti-PT symmetry

Abstract

The intriguing photonic spin Hall effect (PSHE) of reflected Laguerre-Gaussian (LG) beams can be exhibited on the systems with optical anti-parity-time (Anti-PT) symmetry. During the reflection, the left/right circularly polarized (LCP/RCP) components of reflected LG beams are considered. By controlling parameters of the Anti-PT systems, the PSHE of reflected LCP/RCP can be identical and symmetrical with respect to incident-reflected plane (IRP). Due to gain/non-Hermitian effects of designed Anti-PT systems, special PSHE near the strong gain points (SGP) and exceptional points (EPs) can be obtained simulatively. Through analyses in PSHE of reflected LCP on four similar Anti-PT systems, specific conclusions that can even be extended to more general cases. Moreover, simulations of PSHE by simultaneously varying the incident angles * and imaginary/real dielectric constants Im/Re[ε] of the Anti-PT systems, specal PSHE and other novel optical phenomena with real applications can be revealed. So Anti-PT systems not only provide novel ways to regulate the PSHE of reflected LG beams, but also offer possibilities for new optical characteristics of devices.

Chirality-enabled topological phase transitions in parity-time symmetric systems

“…Although natural materials usually exhibit weak chirality [31], an increase in the chirality parameter is possible since chiral metamaterials can dramatically enhance the electromagnetic coupling and have greater chirality [32,33], thereby more effectively regulating the PSHE [27,28,34]. Additionally, non-Hermitian optical systems, by adjusting their geometric and material parameters, can also effectively manipulate the PSHE [35][36][37][38][39][40]. Particularly, systems that exhibit parity-time (PT) symmetry serve as powerful tools for manipulating PSHE [35,36,39,41,42].…”