Investigation of bidirectional dual-channel long-distance chaos secure communication based on 1550nm vertical-cavity surface-emitting lasers

Abstract

Based on the chaos synchronization between two pairs of corresponding linear polarization modes in two 1550 nm vertical-cavity surface-emitting lasers (1550 nm-VCSELs) subject to optical injection of common chaotic signals, a novel bidirectional and dual-channel long-distance chaos secure communication system is proposed. The chaotic synchronization characteristics, bidirectional dual-channel communication performance, and the influences of the fiber channel on the message transmission are numerically investigated. Results show that, driven by a common chaotic signal generated from a driver VCSEL (D-VCSEL), two pairs of responding linear polarization modes in two response 1550nm-VCSELs (R-VCSELs) can be synchronized completely and isochronally. Meanwhile, the synchronization coefficients between the two pairs of responding linear polarization modes in D-VCSEL and R-VCSELs are low. Based on the high quality chaos synchronization between two pairs of responding linear modes in two R-VCSELs, bidirectional and dual-channel chaos secure communication can be achieved. After adopting a single mode polarization-maintaining fiber (or dispersion-shifted polarization-maintaining fiber), for 2.5 Gbit/s messages, the Q factor of the decryption signals after transmitting 60 km (or 200 km) can be more than 6.