Experimental and theoretical investigation of statistical regimes in random laser emission

摘要

We present a theoretical and experimental study aimed at characterizingstatistical regimes in a random laser. Both the theoretical simulations and theexperimental results show the possibility of three region of fluctuationsincreasing the pumping energy. An initial Gaussian regime is followed by aL\'evy statistics and Gaussian statistic is recovered again for high pump pulseenergy. These different statistical regimes are possible in a weakly diffusiveactive medium, while the region of L\'evy statistics disappears when the mediumis strongly diffusive presenting always a Gaussian regime with smooth emissionspectrum. Experiments and theory agree in identification of the key parametersdetermining the statistical regimes of the random laser.