Synchronization of chaotic semiconductor laser dynamics on subnanosecond time scales and its potential for chaos communication - art. no. 011801

We present experimental evidence for the synchronization of two semiconduct or lasers exhibiting chaotic emission on subnanosecond time scales. The tra nsmitter system consists of a semiconductor laser with weak to moderate coh erent optical feedback and therefore exhibits chaotic oscillations. The rec eiver system is realized by a solitary semiconductor laser in which a fract ion of the transmitter signal is coherently injected. We find that for a co nsiderably large parameter range, synchronized receiver output can be achie ved. We discuss the physical mechanism and demonstrate that the receiver ac ts as a chaos pass filter, which reproduces the chaotic fluctuations of the transmitter laser, but suppresses additionally encoded signals. Signal ext raction at frequencies of up to 1 GHz has been achieved. Thus we provide a simple and robust optical chaos synchronization system that is promising fo r the realization of communication by sending signals with chaotic carriers .