Transient characteristics of chaos synchronization in a semiconductor laser subject to optical feedback.

We have investigated the transient characteristics of two types of chaos synchronization in a semiconductor laser subject to optical feedback: complete synchronization and strong injection locking-type synchronization. We have calculated the statistical distribution of the transient response time of synchronization when the initial position in the starting attractor is varied. For complete synchronization, the distribution of the transient response time has much larger average and variance than the average period of the chaotic oscillations. Conversely, a short transient response time is obtained for strong injection locking-type synchronization. We found that the transient response time is dependent upon the maximum Lyapunov exponent of the chaotic temporal waveform for complete synchronization, whereas it is almost constant for strong injection locking-type synchronization.