Precise identification of graphene layers at the air-prism interface via a pseudo-Brewster angle.

We propose a simple method for the precise identification of graphene layers at the air-prism interface via a pseudo-Brewster angle, where the horizontally polarized reflection is close to zero. We find that the pseudo-Brewster angle is sensitive to the variation of graphene layers where the pseudo-Brewster angle is approximately linearly increased about 0.5 deg as the layer numbers increased. Furthermore, the sensitivity of the pseudo-Brewster angle can be greatly enhanced and reaches 0.04 deg by eliminating the influence of the cross-polarization effect. Our scheme can provide a simple and effective method to identify the layer numbers of graphene.