One-decoy-state quantum key distribution with advantage distillation based on planar-lightwave-circuit-integration modules

Photonics integrated circuits provide a stable, compact and robust platform for the implementation of quantum key distribution (QKD), which can generate information-theoretic secure keys between distant parties. Here, we present a high-speed QKD tests with silica planar lightwave circuits based asymmetric Mach-Zehnder interferometer modules. To further enhance system performance and reduce system complexity, we employ the advantage distillation (AD) algorithm alongside the one-decoy method. The AD algorithm can effectively extract strongly correlated bit pairs from weakly correlated bit pairs, thereby significantly improving the key rate over long distances, where traditional post-processing methods fail to generate keys. With a clock rate of 625 MHz, our system achieves composable secret key rates of 3.32 Mbps at 2 dB loss and 1.85 kbps at 18 dB loss, respectively. These results represent the first experimental validation of AD algorithm, and pave the way for the development of QKD networks with photonic integration.