Experiment on 10-Gb/s message transmission using an all-optical chaotic secure communication system

We experimentally demonstrate 10-Gb/s message transmission using an all-optical chaotic secure communication system. In this system, a semiconductor laser subject to mirror optical feedback, operating under a high bias current, is employed as the transmitter. Owing to the high bias current, the transmitter's relaxation oscillation frequency is greatly increased, and consequently, the carrier bandwidth of the transmitted message is also enhanced. By injecting the bandwidth-enhanced signal into an open-loop receiver, we establish a chaos synchronization with a correlation coefficient of 0.94 between the transmitter and the receiver. Based on the high-quality chaos synchronization, a 10 Gb/s message is experimentally encrypted and decrypted with a bit error ratio (BER) below 3.8 x10(-3), i.e., the hard decision forward error correction (HD-FEC) threshold. Bit error analysis indicates that the transceiver, using chaotic decryption, has a BER below the HD-FEC threshold over a wide parameter region. In this parameter region, it is difficult for an eavesdropper using direct decryption to obtain a message with a BER below the HD-FEC threshold.