Synchronisation recovery in unidirectionally coupled semiconductor lasers

Numerical investigation of chaos synchronisation shows that high quality synchronisation is possible in unidirectionally coupled semiconductor lasers using a distorted coupling field. Distortion is achieved through the inclusion of a filter in the coupling path, revealing the ability of the slave laser to compensate for filtering, and generate an output field highly correlated to the original, uncorrupted field of the master laser. The synchronisation recovery is attributed to the regeneration of suppressed frequency components resulting from a resonant frequency mismatch between master and slave. The effects of filtering on the generalised and identical synchronisation regimes are discussed and the underlying physical mechanism is described in terms of the injection rate dependence of the resonant frequency.