Photonic spin Hall effect of vortex beams around the Brewster angle and its weak measurements

Abstract The photonic spin Hall effect (PSHE) around the Brewster angle exhibits many intriguing features. However, previous Brewster angle related PSHE studies have predominantly focused on non-vortex beams, with research on vortex beams remaining relatively scarce. Furthermore, their models of PSHE and weak measurement suffer from certain limitations and inadequacies. In this work, we first established a theoretical model for the PSHE of vortex beams and its corresponding weak measurement. The validity of the established models was experimentally verified using a weak measurement system. Subsequently, we analyzed the characteristics of the PSHE of vortex beams around the Brewster angle. It is found that, unlike non-vortex beams, the photonic spin splitting (PSS) shifts of left- and right-handed components for vortex beams reflected around the Brewster angle are no longer symmetric. Instead, they maintain the same direction while exhibiting distinct magnitudes of shift. Of course, vortex beams also share some characteristics with non-vortex beams. For instance, the PSS shift of vortex beams also undergoes sharp changes and is significantly enhanced near the Brewster angle, and so on. Additionally, the impact of the intrinsic orbital angular momentum on the PSHE is revealed. These results and findings hold potential applications in fields such as photonic manipulation, precision measurement, and high-sensitivity sensing and detection.