Abstract

Semiconductor lasers arc known to be sensitive to an external feedback and to exhibit rich dynamical behaviour. To date, the deterministic dynamics observed is on a time scale of the order of the external cavity round trip time τ (typically ~ a few nanoseconds), while low-frequency fluctuations, recently attributed to chaotic itinerancy, are observed near the threshold of the solitary laser with a buildup time of (10–15)τ. In this report, we provide first experimental evidence of low-frequency limit cycles and chaos in such a laser with single mirror external feedback. The dimensionality of the chaos is found to depend on the number of cavity modes; low for nearly single-mode and high for multi-mode operations, respectively.

© 1996 IEEE