Purcell enhanced and tunable single-photon emission at telecom wavelengths from InAs quantum dots in circular photonic crystal resonators

Abstract: Embedding semiconductor quantum dots into bullseye resonators has significantly advanced the development of bright telecom quantum light sources for fiber-based quantum networks. To further improve the device flexibility and stability, the bullseye approach should be combined with a pin diode structure to enable Stark tuning, deterministic charging, and enhanced coherence. In this work, we fabricate and characterize photonic structures incorporating hole gratings that efficiently support charge carrier transport while maintaining excellent optical performance. We report bright, Purcell-enhanced single-photon emission in the telecom C-band under above-band and phonon-assisted excitation. Additionally, we present electrically contacted resonators, demonstrating wide range tuneability of quantum dot transitions in the telecom O-band. These results mark significant steps toward scalable and tunable quantum light sources for real-world quantum photonic applications.