Integrated secure communication and sensing based on simultaneous chaotic encryption and vibration detection with an RE-LFM signal

The integration of sensing capabilities into secure optical transmission systems is emerging as a pivotal strategy for proactive security threat warning and anomaly detection. However, existing integrated sensing and communication (ISAC) schemes primarily focus on resource sharing, often overlooking the intrinsic security of the communication signals themselves. To address this critical gap, we propose and experimentally demonstrate a novel, to our knowledge, integrated secure communication and sensing (ISCAS) scheme based on simultaneous chaotic encryption and vibration detection utilizing a specially designed random envelope fluctuation linear frequency modulation signal. This uniquely designed signal serves a dual purpose: its random envelope facilitates physical layer encryption, while its LFM nature enables high-precision sensing. As a proof-of-principle demonstration, a 28 Gb/s on-off keying (OOK) confidential signal is securely transmitted over a 20 km single-mode fiber link. Simultaneously, a 1 kHz sinusoidal vibration applied at the 18 km point is detected and localized with an error of only 11.45 m. Our work validates an integrated solution that concurrently ensures information confidentiality and channel-sensing capability, paving the way for more resilient and intelligent optical networks.