A new transfer matrix method to calculate the optical absorption of graphene at any position in stratified media

A new transfer matrix method is developed based on the electromagnetic boundary conditions that Maxwell's equations required. Compared with the traditional transfer matrix method, the new method can be used to calculate the optical absorption of any layer at any position in stratified media. By using this new method, we investigate the optical absorption properties of a single graphene sheet in one-dimensional photonic-crystal (1DPC) heterostructures. We demonstrate that the optical absorption of graphene can be greatly enhanced up to almost 100% by the use of the 1DPC heterostructures because of the strong photon localization in the layer of graphene