Figure 5: Statistical mixture and multiscale turbulent behaviour above the threshold in Er-RFL.
(a) Semi-log plot of the distribution P(x) of experimental intensity increments x (blue circles) in the regime well above threshold, at the excitation power (normalized by the threshold value) P/Pth=2.92 and the prediction from the hierarchical model (2) for the statistical mixture (11) (red line). The individual components of the mixture, given by two Meijer G-distributions with N=6, are shown by green lines. The expected rise in the number of relevant time scales (N=6) upon increasing the excitation power is consistent with the multiscale turbulent cascade behaviour of the intensity fluctuations dynamics in Er-RFL above threshold. The inset shows the corresponding time series of intensity increments. (b) Log–log plot of the density function f(ε) of the experimental variance series ε(t) (blue circles) and the hierarchical model prediction for the statistical mixture (12) (red line), with same parameters as in a. The individual components of the statistical mixture are shown by green lines. The inset displays the compounding of ε(t) with a Gaussian function (red line) and the experimental distribution (black circles).
