Spin-Dependent Splitting Rotation of a Gaussian Beam Reflected From an Air–Glass Interface

We investigate the spin-dependent splitting systematically by considering spin Hall effect of light and in-plane spin separation of light simultaneously, when a Gaussian beam is reflected from an air-glass interface. It is revealed that there exhibits a spin-dependent splitting rotation with the increase of the polarization angle, and the rotation direction and speed can be controlled by the incident angle. Remarkably, with the polarization angle increasing from 0° to 90°, the splitting rotates 180° clockwise in total when the incident angle is less than Brewster angle, whereas it rotates an angle under 90° counterclockwise first and then clockwise return to the original position when the incident angle is larger than Brewster angle. Their initial rotation speeds of splitting to xr direction both become larger as the incident angle approaches to Brewster angle, therefore when the incident angle is equal to Brewster angle, the splitting only forms a 90° clockwise rotation. These general laws of spin-dependent splitting rotation are demonstrated by instances, and the rotation behaviors are considered as a result of various proportions of transverse spin separation and in-plane spin separation. This research provides a feasible way to manipulate the photon spin in optical nanodevice.