Experimental demonstration of photonic crystal resonator enabling wavefront shaping and beam steering

A directional resonator composed of an 8×8 dielectric rod PhC array with square lattice has been proposed to modulate isotropic radiation of point light source into two directional emitting beams. A two-dimensional microwave field scanning system was utilized to experimentally verify the simulation results of photonic crystal (PhC) array resonance and beam manipulation, agreeing well with the simulation predicting strong fundamental resonance at 14.3 GHz near the band edge. The measured internal field reveals uniform phase with a standing wave pattern, and the external field displays highly collimated plane wavefronts. The PhC array resonator transforms an omnidirectional point source into a directed beam emitter, proving band-edge resonance enables wave redirection and self-collimation radiation simultaneously.