CPFSK-Modulated Soliton-Based Ultra-Long-Distance Laser Synchronization for Secure Optical Communications

Abstract

Abstract We propose a novel ultra-long-distance synchronization method for semiconductor lasers, using CPFSK-modulated soliton pulses as the common drive signal. This approach leverages the stability of solitons in long-haul fiber transmission and the continuous phase of CPFSK modulation for reliable synchronization. Experimental results demonstrate synchronization of distributed feedback lasers over an 8191-km fiber link, outperforming traditional chaos-based methods by achieving an 8-fold increase in transmission distance without requiring complex compensation hardware. Additionally, our method preserves communication capacity by avoiding the need for a dedicated channel for analog drive signals, offering a promising solution for secure, high-performance optical communication in backbone and submarine networks.