Spectral-luminescent and lasing properties of merocyanine dye solutions in presence of silver nanoparticles

The effect of silver nanoparticles (NPs) on the spectral-luminescence and lasing properties of an ethanolic solution of positive solvatochromic merocyanine dye is studied. Increases in the absorption cross section, intensity, and duration of dye fluorescence are observed upon the addition of NPs to the solution. This leads to a decrease in the merocyanine lasing threshold. As a result, laser generation can be obtained in the presence of silver NPs ($C_{\mathrm{Ag}}$ = 10$^{-12}$ mol/L) at a dye concentration (10$^{-4}$ mol/L) at which it cannot be achieved in the absence of NPs. It is noteworthy that the power density of laser pumping in the former case is lower than in the latter case.