Spin displacements of a Gaussian beam at an air-multilayer-film interface

We theoretically and experimentally study the unique spin displacements of a linearly polarized Gaussian beam reflected from an air-multilayer-film interface with effective complex reflection coefficients. It is found that the left-and right-handed spin components exhibit distinct intensity distributions and manifest unequal values of displacements. Furthermore, the displacements are very sensitive to the layers' thickness. This provides an efficient pathway for controlling the spin displacements of light, such as enhancement of spin displacements to microns at specific incident angles. The experimental results with P-and S-polarized light are in good agreement with the theoretical predictions.