Synchronization of feedback-induced chaos in semiconductor lasers by optical injection

In this paper, synchronization of chaotic oscillations in semiconductor lasers by optical injection in a transmitter-receiver configuration is studied numerically. A chaotic signal is generated from a semiconductor laser with optical feedback in the transmitter and is injected into the receiver laser without optical feedback. We examined the conditions of chaotic synchronization in the system. As a result, we observed complete chaos synchronization within a finite area of very small parameter mismatch between the two laser systems. In addition, chaotic oscillation synchronized by amplification phenomena was observed in the ordinary injectionlocking regime with higher optical injection ratios. We demonstrated that synchronization of chaotic oscillations by amplification results from a kind of injection locking under chaotic light injection and is very tolerant to the parameter mismatch between the two lasers, in contrast to the complete synchronization case.