Nano/microbubbles enhanced diffuse plasmonic nanoparticle-dye random laser

Random lasers containing plasmonic nanoparticles (NPs) can exhibit speckle-free and tunable lasing emission. However, understanding of the physical mechanisms of the NPs enhancement that give rise to the emission with coherent feedback is poorly understood [1]. It has been suggested that these sharp emissions with linewidth less than 1.0 nm depend on several processes, including random variations of the refractive index of the gain medium, absorption induced localization, amplified extended modes and intrinsic quasimodes [2,3]. Better understanding of the lasing mechanisms would allow novel designs to balance losses and maximize emission for several applications, i.e. bio-imaging, photonics barcode and friend-foe identification [4].