Two-dimensional plasmonic multilayer as an efficient tool for low power random lasing applications

Multi wavelength lasing is desired in two-dimensional flexible plexcitonic nanostructures through surface lattice plasmon amplification. For this purpose, gold nano-rods covered by the gold dispersed Rhodamine B was used as the first gain media. Then, the spacer layer by Poly-Vinyl-Pyrrolidone polymer was implemented to enhance the total internal reflection between polydimethylsiloxane substrate and this polymer. Finally, it was coated by methylene Blue dye with three different gold concentrations as the second gain media. To achieve multi-wavelength random laser, these three layers pumped by nanosecond green laser and the lasing were collected by spectrometer due to band-edge lattice plasmons in the arrays of plasmonic nano rods in a homogeneous environment. Based on the results, narrow emission peaks were emerged with a full width at half maximum less than 2 nm for every wavelength region, and threshold lasing reduced to the minimum value, along with the maximum emission intensity of multi-wavelength region.