“Room temperature polariton lasing in semiconductor microcavities”

Phys. Rev. Lett. 98, 126405 (2007)

Abstract:We observe a room-temperature low-threshold transition to a coherent polariton state in bulk GaN microcavities in the strong-coupling regime. Nonresonant pulsed optical pumping produces rapid thermalization and yields a clear emission threshold of 1 mW, corresponding to an absorbed energy density of 29 u.J cm.2, 1 order of magnitude smaller than the best optically pumped (In,Ga)N quantumwell surface-emitting lasers (VCSELs). Angular and spectrally resolved luminescence show that the polariton emission is beamed in the normal direction with an angular width of .10 deg. and spatial size around 5 u.m.