Manipulating radiation beams by symmetry of magnetic photonic crystals

We theoretically and experimentally study the radiation of current line source embedded in two-dimensional photonic crystals (PCs) made of ferrite rods. Depending on the symmetry of the PCs, the source radiation working at the band edge of the PCs can be multiple or single beam radiation with narrow beam width. Different ways to change the PC symmetry are proposed. Taking advantage of tunable bandgap of the magnetic PC and by lowering the symmetry of the PC, the radiation direction and its working frequency can be reconfigured by bias magnetic field. Experiments demonstrate the dependence of radiation on the PC symmetry.