All-fibred, telecom technology compatible, room temperature single-photon source

Abstract

Single photon sources are essential building blocks for fundamental quantum optics, and quantum information networks. Their widespread use is currently hindered by impractical features, such as the need for operation at cryogenic temperatures and emission wavelengths lying outside telecom windows. Taking advantage of telecom technology and point defects in GaN crystals, we present, for the first time, the development of a fully-fibered source of single photons operating at room temperature, emitting photons in the telecom O-band and fulfilling the standards of telecom photonics. We characterise an emitter producting single photons at the wavelength of 1292 nm, a spectral broadening compatible with CWDM channels of 13 nm, and a brightness of 25 kcps per mW of pump power. The source shows a signal-to-noise ratio of 16.5 and a purity g⁽²⁾(0) = (5.9 ± 0.5) × 10^-2 at room temperature, showing high potential for being integrated transportable quantum cryptography devices.