A waveguide structure is provided. The waveguide structure includes a photonic crystal structure comprising gyromagnetic materials arranged in a two-dimensional lattice formation that exhibits a plurality of one-way modes produced as a result of magneto-optic effects. One or more confining barriers are positioned around the photonic crystal structure so as to allow the one-way modes to propagate through the photonic crystal structure. One or more radiation sources are positioned in or around the photonic crystal structure so as to couple electromagnetic energy into and out of the waveguide. One or more static external magnetic field sources induce the magneto-optic effects such that the one-way modes are allowed to propagate in one direction in the photonic crystal structure.