Plug&play fibre-coupled 73 kHz single-photon source operating in the telecom O-band

A user-friendly, fiber-coupled, single-photon source operating at telecom wavelengths is a key component of photonic quantum networks providing long-haul, ultra-secure data exchange. To take full advantage of quantum-mechanical data protection and to maximize the transmission rate and distance, a true quantum source providing single photons on demand is highly desirable. This great challenge is tackled by developing a ready-to-use semiconductor quantum-dot-based device that launches single photons at a wavelength of 1.3 mu m directly into a single-mode optical fiber. In the proposed approach, the quantum dot is deterministically integrated into a nanophotonic structure to ensure efficient on-chip coupling into a fiber. The whole arrangement is integrated into a 19" compatible housing to enable stand-alone operation by cooling via a compact Stirling cryocooler. The realized source delivers single photons with a multiphoton events probability as low as 0.15 and a single-photon emission rate of up to 73 kHz into a standard telecom single-mode fiber.