Total Reflection-Induced Efficiency Enhancement of the Spin Hall Effect of Light
Minkyung Kim, Dasol Lee, Thi Hai‐Yen Nguyen, Hee‐Jo Lee, Gangil Byun, Junsuk Rho
Abstract
The spin Hall effect of light (SHEL) refers to the spin-dependent and transverse splitting of oblique incidence that occurs in both refraction and reflection. Enhancement of the SHEL is generally accompanied by a degradation in the efficiency. Recently, an anisotropic metamaterial has been proposed to attain a large SHEL with near-unity efficiency, but is limited to a horizontally polarized incidence. Here, a new approach to achieve a large SHEL and high efficiency simultaneously for arbitrarily polarized incidence is proposed by exploiting total external and internal reflection. The total reflection at the interface of a dense-to-sparse medium yields a theoretical maximum of the shift that is allowed for a unity efficiency. The SHEL can be further enhanced by increasing the refractive index contrast. Furthermore, we suggest a three-dimensional isotropic metamaterial that is designed to have an index below unity as a platform to experimentally demonstrate the SHEL with high efficiency. Our work will find wide applications in spin-dependent photonic devices.