Experimental Observation of Strong Edge Effects on the Pseudodiffusive Transport of Light in Photonic Graphene

摘要

Photonic graphene is a two-dimensional photonic crystal structure that is analogous to graphene. Wenuse 5 mm diameter Al2O3 rods placed on a triangular lattice with a lattice constant ¼ 8mm to create annisolated conical singularity in the photonic band structure at a microwave frequency of 17.6 GHz. At thisnfrequency, the measured transmission of microwaves through a perfectly ordered structure enters anpseudodiffusive regime where the transmission scales inversely with the thickness of the crystaln( * 5). The transmission depends critically on the configuration of the edges: distinct oscillations withnan amplitude comparable to the transmission are observed for structures terminated with zigzag edges,nwhile these oscillations are absent for samples with a straight edge configuration.