Dark-field spin Hall effect of light

While an optical system's symmetry ensures that the spin Hall effect of light (SHEL) vanishes at normal incidence, the question of howclose to the normal incidence can one reliably measure the SHEL remains open. Here we report simulation and experimental results on the measurement of SHEL at similar to 0.12 degrees away from normal incidence in the Fourier plane of a weakly focused beam of light, reflected at an air-glass interface. Measurement of transverse spin-shift due to <0.05 degrees polarization variation in the beam cross section along the X- and Y-directions is achieved in the dark-field region of the reflected beam. Our ability to measure the SHEL at near-normal incidence with no moving optomechanical parts and significantly improved sensitivity to phase-polarization variations is expected to enable several applications in the retro-reflection geometry including material characterization with significant advantages. (c) 2022 Optica Publishing Group

Automated summary

This study presents simulation and experimental results on measuring the spin Hall effect of light (SHEL) at approximately 0.12 degrees away from normal incidence. The measurement is achieved by detecting the transverse spin-shift caused by polarization variations in the reflected beam. This research opens up possibilities for applications in material characterization using retro-reflection geometry.