Transport properties of one-way EM waveguide formed at the interface between metal and two-dimensional photonic crystal

We have studied numerically transport properties unidirectional waveguide formed by the interface of a metal and two-dimensional photonic crystal where only a forward propagating surface plasmon polariton (SPP) mode is allowed to propagate. To investigate transport properties of the structures within this frequency range we used finite-difference time-domain (FDTD) method based on Z-transform that allows calculating the propagation of EM waves through media with full tensorial magneto-optic permittivity. In particular, we studied how the unidirectionality demonstrates itself in two different waveguide configurations when magnetic field is gradually switched on and how the unidirectional propagation is affected in the presence of the metallic wall introduced at the boundary belonging to allowed propagating mode and that is perpendicular to the metal-PhC interface. The interpretation proposed addresses the role of scattering that occurs in the waveguide and its contribution to the distribution of the energy flow.