Independent tuning of quantum dot frequencies in a photonic crystal cavity

One of the main obstacles to coupling multiple quantum dots (QDs) to a single nanocavity mode in a cavity quantum electrodynamics system is the ability to independently tune the quantum dot frequencies. We demonstrate that in a specially designed GaAs photonic crystal membrane structure with two embedded QD layers, the QD emission frequencies of one layer can be tuned independently of the other by applying a voltage across only one of the QD layers. Initial results on coupling two QDs to a single cavity mode are discussed.