Mode-Switching induced super-thermal bunching in quantum-dot microlasers

The research leading to these results has received funding from the German Research Foundation via CRC 787 and from the European Research Council under the European Union's Seventh Framework ERC Grant Agreement No. 615613. We gratefully acknowledge technical support by qutools GmbH.The super-thermal photon bunching in quantum-dot micropillar lasers is investigated both experimentally and theoretically via simulations driven by dynamic considerations. Using stochastic multi-mode rate equations we obtain very good agreement between experiment and theory in terms of intensity profiles and intensity-correlation properties of the examined quantum-dot micro-laser’s emission. Further investigations of the time-dependent emission show that super-thermal photon bunching occurs due to irregular mode-switching events in the bimodal lasers. Our bifurcation analysis reveals that these switchings find their origin in an underlying bistability, such that spontaneous emission noise is able to effectively perturb the two competing modes in a small parameter region. We thus ascribe the observed high photon correlation to dynamical multistabilities rather than quantum mechanical correlations.Publisher PDFPeer reviewe