Long-distance multi-channel bidirectional chaos communication based on synchronized VCSELs subject to chaotic signal injection

●Compared with electronic chaos communication, optical chaos communication can offer very large bandwidth and low attenuation of fiber channel, which can be more secure and reliable.●In this paper, based on the two synchronized VCSELs, we proposed a long-distance multi-channel bidirectional chaos communication system, and investigated its synchronization properties and communication performances theoretically.●Chaotic signals can be obtained from D-VCSEL and R-VCSELs in both x-LP and y-LP modes, simultaneously.●Besides, high quality chaos synchronization between R-VCSEL1 and R-VCSEL2 in two LP modes can be achieved while poor synchronization between D-VCSEL and R-VCSEL is kept under suitable parameters.●Meanwhile, we also studied the parameters mismatch between the two R-VCSELs.●Furthermore, we investigated the effects of varied qualities of chaos synchronization on communication performances by regulating different internal parameters mismatch, simultaneously.●The result shows that the system is sensitive to synchronization property.●Finally, based on high quality synchronization, multiple 10 Gbit/s long messages can be efficiently encrypted and decrypted bidirectionally in 180 km SMF multi-channel through different paths by numerical simulation after adopting DCF links to compensate chromatic dispersion, which still be accompanied by the BERs of less than 10−9 in all channels.●We hope our research will be useful for the realization of optical chaos communication networks.

A novel long-distance multi-channel bidirectional chaos communication system over multiple paths based on two synchronized 1550 nm vertical-cavity surface-emitting lasers (VCSELs) is proposed and studied theoretically. These two responding VCSELs (R-VCSELs) can output similar chaotic signals served as chaotic carrier in two linear polarization (LP) modes with identical signal injection from a driving VCSEL (D-VCSEL), which is subject to optical feedback and optical injection, simultaneously. Through the numerical simulations, high quality chaos synchronization between the two R-VCSELs can be obtained. Besides, the effects of varied qualities of chaos synchronization on communication performances in 20 km single mode fiber (SMF) channels are investigated by regulating different internal parameters mismatch after adopting chaos masking (CMS) technique. With the decrease of the maximum cross correlation coefficient (Max-C) between the two R-VCSELs, the bit error rate (BER) of decoded message increase. Meanwhile, the BER can still be less than 10−9 when the Max-C degrades to 0.982. Based on high quality synchronization, when the dispersion compensating fiber (DCF) links are introduced, 4n messages of 10 Gbit/s can transmit in 180 km SMF channels over n coupling paths, bidirectionally and simultaneously. Thorough tests are carried out with detailed analysis, demonstrating long-distance, multi-channel, bidirectional chaos communication based on VCSELs with chaotic signal injection.