Study On Switching The Directions Of Spin Accumulation Of Spin Hall Effect Of Light

The spin Hall effect of light is a new Hall effect, which has drawn considerableattention because of the important potential applications. The spin Hall effect of lightpaves a new way to manipulate photon and provide support for developing a newgeneration of spin-photonic devices. The SHEL also has important application innano-optics, quantum information, and semiconductor physics. In this paper, themethods of switching the direction of spin accumulation are investigated, which isbased on the theory of the spin Hall effect of light. The results show that the directionof spin accumulation in reflection can be reversed by changing the angle of incidenceand incident polarization angle and the direction of spin accumulation in refractioncan be reversed by changing the refractive index difference. The subject provides anew path for regulating the spin Hall effect of light, and has potential applications infuture spin-photonic devices. It not only has scientific significance but also haspractical value. In this paper, the following works are as below:Firstly, reviewing the theory of angular spectrum of the plane wave, themonochromatic wave could be seen as different propagation direction of plane wavesuperposition in light field on one plane. The paraxial propagation equation ofGaussian beams in the conventional media is derived from plane angle spectrum oftheoretical. The transmission characteristics of Gaussian beam in the conventionaldielectric interface are revealed. Analyzing the spin Hall effect from the point of viewof conservation of angular momentum.Secondly, based on the Gaussian beam propagation mode land according to thetheory of the plane wave angular spectrum and Fourier transform theory, theleft-handed circularly polarized light and the right-handed circularly polarized light ofthe parallel polarization component and the vertical polarization component in thespin Hall effect of light is analyzed. Discuss the angle of incidence and polarizationangle influence on the spin accumulation direction respectively. The study shows thatfor vertical polarization component, the direction of spin accumulation is unreservedincreasing with the incident angle. For horizontal polarization component, thedirection of spin accumulation will reverse increasing with the incident angle, and thetransverse shift of the left-handed circular polarization and the right-handed circularpolarization is instantly increased near the Brewster angle. The direction of spin accumulation will flip with increase of the polarization angle of incident light whilethe incident angle is fixed and less than Brewster angle. But the direction of spinaccumulation won’t flip with polarization angle if the incident angle is more thanBrewster angle. The results show that the direction of spin accumulation can beswitched by adjusting the polarization angle of incident light while the incident angleis fixed and less than Brewster angle. In addition, we use weak measurementtechniques to verify theoretical results. Experimental results are consistent totheoretical results.Thirdly, the change of refraction differential refractive influence on the directionof spin accumulation is investigated. The study shows that the direction of the spinaccumulation will reverse because of the sign of transverse shift of the left and rightcircular polarization light changed with the refractive index of the first layer. Itprovides the theoretical basis for regulating the spin Hall effect of light.