Purcell-Enhanced Single Photons at Telecom Wavelengths from a Quantum Dot in a Photonic Crystal Cavity

TL;DR

This paper demonstrates Purcell-enhanced single photon emission from InAs/InP quantum dots in a photonic crystal cavity at telecom wavelengths, with stable single photon purity up to 25K, advancing quantum communication technology.

Contribution

It introduces a telecom-band quantum dot single photon source with Purcell enhancement and temperature tuning, suitable for cryogen-free quantum communication applications.

Findings

Achieved a Purcell factor of 5 with a 340 ps radiative lifetime.

Maintained single photon purity up to 25K.

Demonstrated temperature tuning of emission wavelength.

Abstract

Quantum dots are promising candidates for telecom single photon sources due to their tunable emission across the different low-loss telecommunications bands, making them compatible with existing fiber networks. Their suitability for integration into photonic structures allows for enhanced brightness through the Purcell effect, supporting efficient quantum communication technologies. Our work focuses on InAs/InP QDs created via droplet epitaxy MOVPE to operate within the telecoms C-band. We observe a short radiative lifetime of 340 ps, arising from a Purcell factor of 5, owing to interaction of the QD within a low-mode-volume photonic crystal cavity. Through in-situ control of the sample temperature, we show both temperature tuning of the QD's emission wavelength and a preserved single photon emission purity at temperatures up to 25K. These findings suggest the viability of QD-based, cryogen-free, C-band single photon sources, supporting applicability in quantum communication technologies.