Research On Spin Angle Splitting In Spin Hall Effect Of Light

While a linear polarized beam pass through the inhomogeneous medium,due to the spin-orbit coupling interaction,photons with opposite spin direction will deviate along the direction perpendicular to incidence surface,drift apart and lay separately on each side of the transfer beam's cross section.This transverse displacement not only includes spatial shift,but also includes a very small angular shift.The existing conditions and influencing factors of spatial shift have been numerous studied,but the angular shift is still a new research direction.Thus,spin angle splitting in spin Hall effect of light(SHEL)becomes what this paper focuses on.Based on three-dimensional Gaussian beam transmission models of total internal reflection and Gaussian beam transmission model in layered nanostructures,analyzing spin angle splitting phenomenon in both cases,revealing factors of spin angle splitting,thus put forward the method of using spin angle splitting to control the spin Hall effect of light.The specific work is summarized as follows:First,spin angle splitting phenomenon of beam total internal reflection is studied.The quantitative relationships of incident angle,polarization state and beam transmission distance upon the spin angle splitting of SHEL are revealed,by establishing horizontal polarization and vertical polarization transmission models of beam total internal reflection at the interface from glass to air.It is found that only when the incident angle is bigger than the critical angle,spin angle splitting phenomenon will appear,or there will be only space shift in SHEL,and angular shift decreases with the increase of the incident angle,it also changes with the increase of transmission distance at the same time.It is interesting that transverse shift will reverse because of the influence of spin angle splitting in the case of vertical polarization light.The spin angle splitting phenomenon of SHEL can be explained from the aspect of phase difference between parallel and vertical components of Fresnel reflection coefficient.Second,spin angle splitting phenomenon in layered nanostructures is studied.The qualitative relationships of incident angle,the thickness of medium,beam waist,refractive index gradient,polarization state and beam transmission distance upon the spin angle splitting of SHEL are revealed,by establishing Gaussian beam transmission model in layered nanostructures.The results indicate that only when phase difference between parallel and vertical components of Fresnel refraction coefficient is not 0 or ?,spin angle splitting phenomenon will appear,and spin angle splitting is different in the case of vertical polarization light and parallel polarization light,In addition,when the incident angle is smaller than the Brewster angle,or the refractive index gradient of parallel polarization light is positive and the refractive index gradient of vertical polarization light is negative,transverse shift will reverse.These results will provide some reference value on-further amend the laws of optics and regulate the SHEL.