Broadband high-efficiency polarization-independent Photonic Spin Hall Effect with high structure tolerance for all incident angle

The Photonic Spin Hall Effect (PSHE) manifests as the spin separation of light at an optical interface, exhibiting sensitivity to incident polarization and incident angles. In this study, we demonstrate the attainment of polarization insensitivity of PSHE across all incident angles for a plane-polarized incident wave. Through numerical calculation with horizontally (H) and vertically (V) polarized light, we observe equal magnitude spin separation $\left({\delta }_{\pm }^H={\delta }_{\pm }^V\right)$ in the reflected light from a hemispherical prism-coupled Ag-SiO₂-Ag, based MIM structure. Moreover, our investigation reveals that despite alterations in physical dimensions, the polarization-independent PSHE is preserved, highlighting its robustness and high tolerance to structural modification or fabrication defects. Further the efficiency of presented PSHE is also showing a high value ranging from ∼ 80 % to near 100 %. This enhanced efficiency is crucial for real-world implementations, as it enables the development of advanced photonic devices with improved performance and reliability. Furthermore, the spectral analysis reveals that the PI-PSHE behavior is consistently preserved across the entire broadband range from 400 nm to 1400 nm. This research presents an avenue for developing spin optic devices with polarization and incident angle insensitivity, coupled with large efficiency and high structural tolerance, promising advancements in various applications.