Chaos and control of chaos in diode lasers

Various control algorithms have been explored in which a fractional amount of a chaotic signal, from a system, after being appropriately processed, is fed back to the system itself. We explore the application of this control strategy to diode lasers which are well known to be highly susceptible to external optical feedback resulting in dramatic dynamic destabilisation of the emission leading ultimately to coherence collapse. We report on the first control of chaotic emission from such a system resulting in the selection and stabilisation of a broad spectrum of distinct oscillatory forms. Tracking of the stabilised wave forms with increasing gain of the diode laser is shown to be effective over an extensive range. We further report on controlled bistable operation of various of these wave forms and in ongoing work the stabilisation and tracking of unstable steady states of the laser