One-way transmission through merging of magnetic defect state and optical Tamm states

sTo achieve a new type of one-way transmission, we design a semi-infinite one-dimensional photonic crystal (PC) coated with a magneto-optical (MO) material film. In the surface of this structure there are merging states of MO defect state and optical Tamm state (OTS). We deduce the dispersion equation of the merging states basing on the Bloch theorem of periodic structures and transfer matrix method. There are two nonreciprocal dispersion curves of the merging states for kx and −kx, respectively. The positions of the merging states can be adjusted through changing the thickness of the MO film. With the use of the attenuated total reflection (ATR) prism coupling, we consider a one-way transmission based on a finite one-dimensional PC structure. The simulations by using a finite element method demonstrate the one-way transmission results.