Impact of the incident light polarization on photonic spin splitting around the Brewster angle

In this letter, we theoretically investigate the impact of the incident light polarization on photonic spin splitting induced by the photonic spin Hall effect when a linearly polarized Gaussian beam is reflected from an air-glass interface around the Brewster angle. We calculate the spin splitting shift as a function of the incident light polarization under different incident angles. We find that a tiny variation of the incident light polarization can result in a dramatic change of the spin splitting shift, and the highest sensitivity is up to 6.8 μm/deg . The largest splitting shift can reach 5.3 μm, which is larger than the previously reported values. We also find that the direction of spin accumulation of photons with different spin directions can be switched by adjusting the incident angle around the Brewster angle when the incident light polarization is near the p-polarization. These findings may be useful for precise polarization metrology and photon modulation.