Photonic crystals with anomalous dispersion: Unconventional propagating modes in the photonic band gap

We present an investigation of the optical properties of photonic crystals whose constituent materials exhibit anomalous dispersive behavior. In particular, the anomalous dispersion near resonances may lead to additional propagating modes in the gap of the undoped system for a localized region of wave-vector space. Such a system may be realized by infiltrating quantum dots in polymer suspensions into the pores of two-dimensional high-index photonic crystals. An evaluation of the absorption lengths associated with these unconventional modes and corresponding transmission calculations demonstrate that this effect can be observed in currently accessible structures.