Quantum Communication with Quantum Dots Beyond Telecom Wavelengths via Hollow-Core Fibers

Abstract: Quantum dot single-photon sources are promising for quantum communication. Yet, the most advanced devices operate near 900 nm, where standard single-mode fibers experience significant losses. We address this by employing a hollow-core fiber engineered for low-loss transmission at quantum dot wavelengths, with measured loss of 0.65 dB/km and potentially as low as 0.12 dB/km near 934 nm. The fiber also supports strong classical signals at 1550 nm without adding Raman noise. Using this platform, we transmit all four BB84 polarization states from an InAs quantum dot over 340 m with 0.1% QBER, preserving single-photon purity and indistinguishability even in the presence of a strong classical signal. These results highlight how tailored transmission media enable quantum networks beyond the limits of standard telecom fibers.