Threshold reduction induced by silica nanoparticle-dispersed active layer in diode-pumped microcavity dye laser

We report a vertical microcavity dye laser consisting of a polymeric active random layer doped with silica nanoparticles whose diameters are approximately 100 nm. Pumped by an InGaN-based blue-violet laser diode with pulse duration of 3 ns, single mode laser oscillation was obtained at a wavelength of 530 nm. The threshold pump power decreased from 70 mW/pulse to 49 mW/pulse by adding nanoparticles to the active layer. We found an optimum particle density of 2×1013 cm-3 by measuring threshold pump power to change depending on the particle density in the activity layer