QKD on a Board Limited by Detector Rates in a Free-Space Environment
Alan Mink, Joshua Bienfang
We discuss a high-speed quantum key distribution (QKD) system with the protocol infrastructure implemented on a single printed circuited board that can operate with various photonic subsystems. We achieve sub-nanosecond resolution with serial data receivers operating up to 2.5 Gb/s. Data processing bottlenecks are avoided with pipelined algorithms and controlled data flow implemented in a field-programmable gate array. This eliminates processing on the attached computer and frees CPU cycles for related activities, such as key management and system monitoring. Operating in a laboratory setting, we tested the QKD boards up to their maximum 2.5 GHz transmission rate, and found that under low-link-loss, high-count-rate conditions, timing jitter in the single-photon detectors imposed critical limitations to the maximum achievable throughput.
The Seventh International Conference on Quantum, Nano and Micro Technologies