ACCUMULATED PHOTON-ECHO IN SEMICONDUCTOR MICROCRYSTALLINE QUANTUM DOTS

The nonlinear coherent emission of excitons in CuBr quantum dots was i nvestigated using a phase-stabilized photon-echo technique. The echo s ignal was observed to be quite strong, with the emission efficiency be ing three orders of magnitude larger than that of II-VI semiconductor quantum wells. Time resolving of the echo signal confirmed that the st rong nonlinear emission originates from the accumulation effect of the population grating due to the presence of the bottleneck state. Forma tion and decay kinetics of the population grating was analyzed by taki ng into account the light-induced deexcitation effect.