ABSTRACT: We discuss possible applications of chiral photonic structures involving magnetic components and supporting the phenomenon of electromagnetic unidirectionality. In such periodic arrays, the wave propagating in forward direction has finite group velocity, while the backward propagating wave has vanishing group velocity and greatly enhanced amplitude.We discuss possible applications of chiral photonic structures involving magnetic components and supporting the phenomenon of electromagnetic unidirectionality. In such periodic arrays, the wave propagating in forward direction has finite group velocity, while the backward propagating wave has vanishing group velocity and greatly enhanced amplitude.