Chaotic communication using asynchronous laser diode transmitter/receiver array with optical feedback

Chaotic secure communication in a chaotic laser diode transmitter/receiver array scheme (CLDTRAS) with optical feedback has been described. It uses an array of several transmitters/receivers consisting of a laser diode (LD) with optical feedback as a transmitter LD and one with optical injection as a receiver LD, and the difference in chaotic dynamics between these two types of transmitter/receiver array is utilized to encode a binary message. The effects of the parameter mismatches between the transmitter and receiver LDs on the bit error rate for CLDTRAS and on the synchronization have been studied and compared with each other. It has been shown that CLDTRAS is hardware-dependent and independent of chaos synchronization. Because communication is achieved with an asynchronous LD transmitter/receiver array, it becomes difficult to forge hardware and eavesdrop with forged hardware. Then, we investigate the bit error rate for CLDTRAS against channel noise to show that it is possible to communicate with smaller bit error than the conventional schemes.