Photonic-layer secure 56 Gb/s PAM4 optical communication based on common noise driven synchronous private temporal phase en/decryption
Zhensen Gao, Lei Liao, Biao Su, Qiongqiong Wu, Xulin Gao, Songnian Fu, Zhaohui Li, Yuncai Wang, Yuwen Qin
Abstract
Achieving photonic layer security at the lowest network layer to supplement the upper layer digital cryptography in fiber-optic networks is a constant pursuit but a critical challenge. In this Letter, we propose and experimentally demonstrate a high-speed photonic-layer secure optical communication system based on a novel, to the best of our knowledge, common noise driven synchronous private temporal phase en/decryption scheme, which is capable of supporting high-order modulation formats and enhancing security. A record high bit rate of 56 Gb/s 4-level pulse amplitude modulation (PAM4) confidential signal is successfully encrypted and decrypted by remotely synchronized private noise-like en/decryption signals after secret transmission over 20 km of optical fiber with a bit-error-rate (BER) lower than the hard-decision forward error correction (HD-FEC) limit. The demonstrated scheme may provide a promising way for future ultrahigh-speed photonic-layer secure optical communication.