Strain-Tunable Single-Photon Source Based on a Quantum Dot–Micropillar System

Scalable quantum photonic architectures demand highly efficient, high-purity single-photon sources, which can be frequency matched via external tuning. We demonstrate a single-photon source based on an InAs quantum dot embedded in a micropillar resonator, which is frequency tunable via externally applied stress. Our platform combines the advantages of a micropillar cavity and the piezo-strain-tuning technique enabling single-photon spontaneous emission enhancement via the Purcell effect and wavelength-tunable quantum dots (QDs). Our optomechanical platform has been implemented by integration of semiconductor-based QD–micropillars on a piezoelectric substrate. The fabricated device exhibits spontaneous emission enhancement with a Purcell factor of 4.4 ± 0.7 and allows for a pure triggered single-photon generation with g(2)(0) < 0.07 under resonant excitation. A quantum dot emission energy tuning range of 0.75 meV for 27 kV/cm applied to the piezosubstrate has been achieved. Our results pave the way toward ...