Abstract

Semiconductor lasers with external optical feedback show a variety of complex dynamical behaviour. At moderate feedback levels, nonlinear dynamics are observed in two different time scales; one is fast, in the order of the external cavity round trip time τ, while the other is slow, occurring typically in 10-15τ. When the injection current is close to the pump threshold value of the solitary laser, the systems display sudden power-dropout events on the slow time scale, so-called low frequency fluctuations (LFF). Such a phenomenon has been found to be an intrinsic feature of their operation, in the presence or absence of noise; it is attributed to chaotic itinerancy. In this work, we show that two such high-dimensional laser systems operating in regimes of chaotic itinerancy can be successfully synchronized by appling a non-invasive continuous feedback scheme.

© 1998 IEEE