Observation of Cartesian Light Propagation Through a Three-Dimensional Cavity Superlattice in Silicon Photonic Band Gap Crystals

Fruitful analogies exist between waves like light or sound that propagate in mesoscopic photonic or phononic metamaterials and the elementary excitations in atomic crystals like phonons, electron and spin waves [1]. A peculiar class of wave transport is discretized transport with hopping in all three dimensions on superlattices, as demonstrated in phonons, electrons and spins [2], but not yet for light. Here, a superlattice is a periodic arrangement of a supercell that consists itself of multiple unit cells of an underlying crystal structure [3].