Propagation of photons by hopping: A waveguiding mechanism through localized coupled cavities in three-dimensional photonic crystals

A new type of waveguiding mechanism in three-dimensional photonic band-gap structures is demonstrated. photons propagate through strongly localized de fect cavities due to coupling between adjacent cavity modes. High transmiss ion of the electromagnetic waves, nearly 100%, is observed for various wave guide structures even if the cavities are placed along an arbitrarily shape d path. The dispersion relation of the waveguiding band is obtained from tr ansmission-phase measurements, and this relation is well explained within t he tight-binding photon picture. The coupled-cavity waveguides may have pra ctical importance for development of optoelectronic components and circuits .