Abstract

Excitons are thought to obey boson statistics, when the total excitation density is below a critical value (Mott density).¹ In practice, it is not dear whether populations larger than one for some modes can be achieved below¹ this density. This may not be the case even for selective excitation of a few modes, when rapid diffusion to other modes quickly distributes around the bosons. Indeed, in quantum wells, disorder and interface roughness is a relevant source of fast diffusion into a large region of the phase space. Diffusion is instead quenched for microcavity polaritons. These mixed modes of the optically active exciton and the confined cavity photon have a mass close to the bare cavity photon mass, which is four orders of magnitude smaller than the exciton mass.² Diffusion quenching results from the reduction of the final density of states for any scattering process. Therefore, we expect that large occupation numbers or stimulation effects can be realized for the cavity polaritons.

© 1998 Optical Society of America