Abstract

The language of Solid State Physics has proved to be a very useful tool in generating novel ideas in quantum electrodynamics, especially with respect to the control of spontaneous emission: The analogy between electron-waves in semiconductors and the propagation of electromagnetic waves in wavelength-scale periodic dielectric structures has given rise to the proposal of Photonic Band-Gap (PBG) structures. While three-dimensional PBG structures are very appealing for the complete control of spontaneous emission, their fabrication has proved to be extremely difficult for optical frequencies. Nevertheless, there exists one structure that has the double advantage of being readily fabricated by the existing technological means and of displaying a PBG in all three spatial directions, albeit for only one polarization. It is the planar waveguide composed of two parallel metallic mirrors spaced by L. For electromagnetic waves polarized parallel to the plane of the mirrors, the waveguide presents a cut-off frequency ω_c = π_c/L and a modal dispersion which is parabolic for small wavevectors and is thus reminiscent of the dispersion of conduction electrons in semiconductors.

© 1996 IEEE