Exciton-polariton amplification based on exciton-exciton scattering in a CdTe quantum well

Summary form only given. Final state stimulation is the origin of amplification in optical lasers and atom lasers. Matter-wave amplification based on an incoherent gain medium has yet to be demonstrated, but is very attractive, particularly for the excitonic system, because electrically injected incoherent excitons can amplify probe excitons without requiring a coherent pump laser. In previous work, we have shown final state stimulation using the exciton-exciton scattering of polaritons in a GaAs based microcavity quantum well; the gain was negligibly small due to the small exciton-exciton scattering rate. However, the rate of exciton-exciton scattering at the exciton saturation density is 9 times larger in CdTe microcavity exciton-polaritons compared to those in GaAs.