Purcell-enhanced single photons at telecom wavelengths from a quantum dot in a photonic crystal cavity

We demonstrate Purcell-enhanced single-photon emission from metal-organic vapor-phase epitaxy (MOVPE) grown InAs quantum dots (QDs) on InP, emitting near the telecom C-band and integrated into L3 photonic crystal cavities. Using pulsed quasiresonant excitation (LA-phonon sideband), we measure a radiative lifetime as short as 340ps, yielding a Purcell factor of 5. Temperature tuning shows that single-photon purity remains high up to at least 25K. These findings highlight the potential for bright, high-rate single-photon devices at telecom wavelengths, compatible with cryogen-free operation and future fiber-based quantum communication.