Random lasing films from multifunctional charged optical silica particles

Multifunctional SiO 2 particles with charged and fluorescent properties were synthesized and their films with different thickness were prepared using electrophoretic deposition for random lasing. In case of 50-μm-thick film, when the excitation energy density increases above 25 μJ/cm 2 , spectral narrowing and nonlinear increasing of intensity were observed. To get more information on lasing, single-shot spectrum was measured. Finally, the dependence of the lasing behavior, including the recognition of the existence of a threshold on the film thickness was demonstrated.