Figure 1: Emission spectra and time series of maximum intensities in Er-RFL.
(a–c) Representative samples showing 500 successive emission spectra at each excitation power P (normalized by the threshold value Pth) below [(a) P/Pth=0.72], near [(b) P/Pth=0.99] and above [(c) P/Pth=2.92] the random laser threshold of Er-RFL. Intensities I are displayed in arbitrary units as function of the wavelength λ. The portrayed spectra were collected at times tτ, with integration time window τ=100 ms and dimensionless index t=1,501, 1,502, …, 2,000. (d–f) For each one of the 150,000 spectra in the whole data set, the maximum intensity was recorded, resulting in the long time series I(t), with t=1, 2, …, 150,000, which is shown in d–f for the respective values of P/Pth.
