Effect of hybrid state of surface plasmon–polaritons, magnetic defect mode and optical Tamm state on nonreciprocal propagation

A coupled system of semi-infinite one-dimensional photonic crystal coated with metal and magnetic films is proposed. The properties of hybrid states of surface plasmon–polaritons, magnetic defect mode and optical Tamm state from the system have been studied through the Bloch theorem of periodic structure and the transfer matrix method. In the hybrid states the magneto-optical effect is amplified due to the field resonance amplification at the interface between the metal and magneto-optical material. Tunable nonreciprocal propagation can be achieved from the hybrid states through changing the thickness of magneto-optical material layer. The nonreciprocity is found to be robust to the change of metal thickness.