Ultralow threshold polariton lasing by electron cooling in doped microcavities

Summary form only given. In high-finesse semiconductor microcavities, the dominant excitations are mixtures of light and matter called exciton-polaritons. Due to the distorted shape of the dispersion relation for polaritons, a relaxation bottleneck prevents the realization of low threshold lasing. Here we show that the introduction of a cold electron gas into such structures induces extremely efficient electron-polariton scattering. This process allows the condensation of polaritons into a single low energy state within a few picoseconds, opening the way to a new generation of low-threshold light-emitting devices.