Stimulated emission of excitons into polaritons in a semiconductor microcavity post

Three-dimensional confinement of microcavity polaritons in a small post str ucture can be used to produce quasi-discrete polariton modes. For sufficien tly small structures, the lowest confined polariton mode becomes well isola ted from the other states. We consider the exciton-exciton scattering dynam ics in the micropost system, and injection of moderate amount of excitons. We show that exciton-exciton scattering provides sufficient gain to produce stimulated emission of excitons into confined polaritons, well before coll apse of the Rabi splitting. We also study the statistical properties of thi s matter laser, and beside usual Poisson statistics and linewidth reduction above threshold, we also end a linewidth increase very far above threshold , which is peculiar of this system, and shows Strong similarities to proper ties of some proposed atomic laser systems.