IEEE-NPSS Real-Time Conference

Time interval analyzer with FPGA-based TDC for free space quantum key distribution: Principle and validation with prototype setup

Qi Shen, Sheng‐Kai Liao, Shubin Liu, Jinhong Wang, Wei-Yue Liu, Cheng-Zhi Peng, Qi An

Published Jun 1, 2012• 3 citations

Abstract

Quantum key distribution (QKD) is the most matured application of quantum communication. The time synchronization and system timing jitter are essential to a practical QKD experiment, which can directly influence the quantum bit error rate (QBER) and the final key rate. High precision time-to-digital convertor (TDC) can effectively reduce the system timing jitter, resulting in lower QBER and higher key rate. Here, we introduce a TDC based on a field-programmable gate array (FPGA). Its high resolution of 50 ps, low dead time and large dynamic range can well meet the requirement of the QKD experiment. A free space QKD system setup using the FPGA-based TDC has been built up. The timing precision of the synchronous light and the system timing jitter were tested. The results demonstrate that the FPGA-based TDC could be successfully applied in the QKD experiment.

DOI: 10.1109/rtc.2012.6418107

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