Large cross-polarization rotation of light on graphene

A large cross-polarization (CP) rotation of light is found on the graphene surface experimentally and applied to measuring the layer number of graphene. First, a general propagation model for the polarization of light reflected on the graphene is established. By using this model, it is found that the CP effect rotates remarkably with the incident polarization near the pseudo-Brewster angle. More importantly, such a rotation differs noticeably for graphene surfaces with distinct layers, thereby providing a simple and efficient approach to detect the graphene layer number. Finally, the CP rotation is shown to be accompanied by the rotation of the spin Hall effect of light. Further experiments are performed to validate the theoretical results.