Quantum communication with quantum dots beyond telecom wavelengths via hollow-core fibers

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 0.13 dB/km near 934 nm. The same fiber also supports strong classical signals at 1550 nm without introducing detectable Raman noise. Using this platform, we transmit all four BB84 polarization states from an InAs quantum dot over 340 m with a quantum bit error rate of 0.1% while preserving single-photon purity and indistinguishability even in the presence of a strong classical signal. These results establish an integrated transmission platform that combines a custom-engineered anti-resonant hollow-core fiber with co-existence of classical and quantum channels, enabling practical quantum-dot-based quantum key distribution beyond the conventional telecom bands.