A novel method of measuring the complexity for secure optical communications

We characterize the chaotic dynamics of an optical micro ring resonator subject to amplitude modulate. The simulation results demonstrate that, by changing the modulation coefficient and input power, we can obtain rich nonlinear dynamics, such as, period, bifurcation and chaos. Moreover, we adopt the permutation entropy to quantify the complexity of the resonator´s output, the results not only qualitatively agree with the dynamical changes, but also indicate the complexity of the chaotic regimes. This characterization is relevant for secure optical communications based on chaos encryption.