Enhancement of weak spin-Hall shift using higher-order helical-wavefront beams

Abstract

A weak measurement technique was employed to measure the spin-Hall (SH) effect of light in TM and TE polarized higher-order Laguerre-Gaussian (LG) beams with a helical phase structure in partial reflection. At the cross-position, the intensity distribution is similar to Hermite-Gaussian beams, and away from cross-position it is a deformed LG beam. Coupling between in-plane Goos-Hänchen and out-of-plane SH shifts occur and modify the overall SH shift. The Jones polarization formalism calculation for weak measurement shows that only the angular SH shift is amplified. The cross-polarization effect causes a large horizontal spin splitting of TM polarized beams around the Brewster angle and affects the resultant SH splitting.