Localized surface plasmon resonance improved lasing performance of Ag nanoparticles/organic dye random laser

Abstract

Random lasing threshold reduction and emission enhancement were reported from a suspension of Ag nanoparticles (NPs) in a laser dye doped polymer film. To evaluate the effect of the localized surface plasmon resonance (LSPR) of metal NPs on random lasing from lasing dye, we carry out a comparative study of the random lasing performance of the Ag NPs and SiO2 NPs scattered dye doped polymer films. Random lasing emission was obtained from Ag NPs and SiO2 NPs scattered dye doped polymer films. The threshold was dramatically reduced from 0.01 to 0.003 mJ/pulse as Ag NPs was used as scatters instead of SiO2 NPs. Theoretical simulation indicates that a large localized electric field is built near the Ag particle surface which enhances the absorption of excitation light. Furthermore, excellent overlap of the plasmonic resonance of Ag NPs with the absorption and photoluminescence spectrum of the dye molecules promotes more dye molecules excited simultaneously to the higher energy levels and leads to more effective random lasing performance.