Characterizing configurable transmission modes in plasma photonic crystals using scanning field mapping

A~ fully~ tunable~ plasma~ photonic~ crystal~ is~ used~ to~ control~ the propagation~ of~ free~ space~ electromagnetic~ waves~ in~ the~ S~ to X~ band~ of~ the~ microwave~ spectrum.~ A~ structured~ array~ of discharge~ plasma~ tubes~ are~ arranged~ in~ a~ square~ crystal~ lattice with~ the~ individual~ plasma~ dielectric~ constant~ tuned~ through variation~ in~ the~ plasma~ density.~ Microwave field-mapping is used to characterize the transmitted electromagnetic fields of the tunable~device~operating in waveguiding~and~bending~modes. These modes are obtained by introducing appropriate line defects in the photonic crystal structure by controlling the activity of individual plasma tubes. Comparisons are made of the measured fields to those simulated using commercially-available software.