Changes in normalized permutation entropy during non-coherent pulse-pulse interaction in the laser cavity

2017 
Statistically extreme events, that is to say, the events which have L-shaped probability distribution function (PDF, or in other words L-statistics) and, in particular, the rogue wave (RW) events, constitute a special family of natural phenomena. Curiously, this kind of events is more common than it is believed. It was observed that the behavior of the systems which obey L-shaped statistics is clustered. Periods of high predictability and low volatility are followed by periods of drastic changes and high volatility, for example, RWs [1], earthquakes, epileptic seizures etc. Permutation entropy (PE) is an indicator of dynamical predictability of the system [2, 3] which allows quantization of the predictability or volatility. We report an investigation of using it to characterize the uncertainty period which was observed during pulse-pulse interaction in a long ring laser resonator without a saturable absorber. These resonators, in particular, the resonator built using Er 3 + doped fiber (Fig.1), have polarization dependent instability near the lasing threshold [4] which leads to the generation of pulses propagating with different speed, either randomly or regularly. Using this property, an investigator can observe the mechanism of the pulse-pulse interaction in detail.
    • Correction
    • Source
    • Cite
    • Save
    • Machine Reading By IdeaReader
    4
    References
    0
    Citations
    NaN
    KQI
    []