Non-linear polariton dynamics in II–VI microcavities

Abstract

Angle-resolved optical spectroscopy is employed to investigate polariton dynamics under conditions of high excitations in CdTe-based microcavities. Time-resolved photoluminescence measurements under non-resonant excitation clearly show the suppression of the relaxation bottleneck on the lower polariton branch, followed by the onset of stimulated emission from the ground polariton states at k|| = 0. To probe the coherent dynamics along the lower polariton branch, we use for the first time angle-resolved four wave mixing measurements. A sharp decrease of the dephasing time T2 is observed when pumping at the magic angle at high powers, as a result of stimulated parametric scattering.