Abstract

The effect of weak photon localisation has been used for lasing in the array of randomly distributed scatterers. Periodic arrangements of scatterers, when their spacing matches the wavelength of the propagating light and their refractive index highly contrasted with a surrounding medium, provides the conditions for the formation of a strong localisation or photonic bandgap (PBG). At the PBG region light is strongly bound to any centre from which it is emitted, which means a high probability for the photon to return to its original location after several scattering events, followed by re-adsorption and a cyclic repetition of the process. Under permanent pumping, optical localisation leads to the build up of potentially excited centres in excess of the equilibrium situation without PBG effects and, correspondingly, to increased effectiveness for the electron-photon interaction.

© 1998 IEEE