Electrically tunable single-photon source triggered by a monolithically integrated quantum dot microlaser

Abstract

We report on a quantum dot micropillar-based single-photon source demonstrating tunable emission energy via an applied electric field and driven by an on-chip, high-β, whispering-gallery-mode microlaser. The cavity-enhanced single-photon source is monolithically integrated with an electrically driven, coherent excitation source. The device concept features low laser-threshold currents of a few tens of µA, has a small footprint with a device area of ≅ 200 µm2 and demonstrates high single-photon purity with g(2)(0) as low as 0.07 ± 0.03 under pulsed electrical excitation of the microlaser. The electric field applied along the growth direction of the single-photon emitter allows the emission to be tuned by up to 1.1 meV via the quantum-confined Stark effect, bringing it into resonance with the fundamental mode of the surrounding micropillar resonator for enhanced emission via the Purcell effect.