Abstract: A light emitting device comprising a substrate and a dielectric structure having at least a two-dimensionally periodic variation of dielectric constant which exhibits a spectrum of electromagnetic modes including guided modes of frequencies below a predetermined frequency cutoff and radiation modes of frequencies above and below said predetermined frequency cutoff, the two-dimensionally periodic variation of dielectric constant of the dielectric structure introducing a band gap between the guided modes. A radiation source, such as a quantum well, is associated with said structure, and generates electromagnetic radiation which couples to the radiation modes resulting in radiation extraction from the structure. The band gap allows the radiation to couple to radiation modes rather than to guided modes resulting in radiation extraction from the structure. The structure can be fabricated such that a radiation reflector is disposed between the structure and the substrate.