**Towards a QED for dispersive and absorptive media ** - John Sipe

Artificially structured materials such as nanowires, waveguides, and photonic crystals are typically constructed of semiconductors or metals that are highly dispersive or even absorptive at frequencies of interest. When these nanophotonic structures are studied for applications in quantum optics, a quantum electrodynamics that includes the effects of dispersion and absorption is required. A full microscopic treatment would be excessive, of course. From experiment or theory one usually has the frequency dependence of the position dependent dielectric constant, and at least at the linear level the goal is to build an effective QED for the medium from this alone. We present one approach based on a mode expansion of the fields. It fits naturally into the usual framework used in classical integrated optics to treat fields in nanophotonic structures.