Experimental evidence of bistability in a semiconductor microcavity

Optical bistability in a semiconductor microcavity showing normal mode coupling regime is observed by means of reflectivity and resonant Rayleigh scattering experiments. A third resonance, spectrally lying between the two normal modes, suddenly appears in the optical response when increasing the excitation power. Hysteresis loops are found when monitoring the microcavity optical response at the energy of the third peak. Our experimental findings can not be accounted for simply by exciton bleaching. We conclude that other non-linear mechanisms are relevant in explaining the presence of the third peak and the observed bistable behaviour.