Technology,

Abstract—We have researched the relationship between the luminescence properties, concentration changes, particle size of fluorescent particles and the additional scattering particles, and the random lasing threshold of a new disorder media. Maxwell equations and the rate equations are solved by using the finite difference time domain (FDTD) method directly. We calculate the emission line and the dependence of lasing threshold on the concentration. When Rh6G-SiO2 occupies 4wt % of the sample, the threshold is 8.5μJ/pulse; the impact of the added small scatterers TiO2 on random laser emission is such little that it could be negligible. In addition, the lasing threshold properties of random media under different condition are calculated, and the impact of these factors on the random laser emission is proposed. Finally, the variation of the concentration of fluorescence particles has little influence on random lasing threshold which is immune to external addition of scatterers. Key words-Random laser ； FDTD ； multiple-scattering； laser-dyes I