The Photonic Bound State in a Waveguide with Defect

Abstract

We investigate the single-photon scattering and bound states in a finite coupled resonator waveguide with a defect. We find that there is always a bound state when the number of the resonators are even. However, for an odd number of resonators, whether there exist bound states depends on the size, the inter-resonator coupling strength as well as the detunning of the defect from the other identical resonators.