From normal-mode coupling to lasing: photoluminescence from a semiconductor microcavity

The threshold-like growth of the higher energy photoluminescence from a normal-mode-coupling microcavity was previously attributed to exciton polariton lasing (boser) based on Bose condensation into the upper polariton branch. Experimental evidence is presented here showing that this boser crossover occurs just as normal-mode coupling collapses to the perturbative weak coupling, so that boser action is fermionic after all. I.e., it can be understood as electron-hole recombination within a microcavity with density-dependent emission properties.