Spontaneous emission in coupled microcavity-waveguide structures at the band edge.

We examine spontaneous emission and photon dynamics in a microcavity coupled to a coupled-resonator optical waveguide (CROW) in a photonic crystal. We present an efficient tight-binding approach to obtain the Green tensor in large, arbitrary systems of coupled microcavities. We use this approach to examine spontaneous emission when the microcavity is strongly coupled to the CROW at the band center and band edge. We confirm the validity of weak-coupling theories for microcavities resonant at band center and obtain strong peak splitting in the previously inaccessible case of band-edge coupled structures.