Exciton-Polaritons in Bulk Semiconductors and in Confined Electron and Photon Systems

In these lecture notes I shall review excitons and polaritons in bulk semiconductors and in systems with electron and photon confinement. Emphasis will be on a proper definition of exciton-photon coupling, on the effects of reduced electron and photon dimensionality, and on the conditions for the occurrence of the strong-coupling regime of radiation-matter interaction. In addition to bulk semiconductors, I shall treat exciton-photon interaction in two-dimensional systems like quantum well excitons in planar microcavities and in waveguide-embedded photonic crystals. I shall also consider quantum dots in three-dimensional cavities, comparing the strong-coupling regime in zero dimensions with exciton-polariton physics in higher dimensions.