Surface-Plasmon Enhancement in Random Lasers

D. Davidov

Racah Institute of Physics, The Hebrew University of Jerusalem, Israel

Random lasing results from the interaction of light with disordered amplifying media. More specifically, it is a consequence of multiple light scattering events by dielectric or metallic scatterers and the formation of closed loop paths of the scattered light. This feedback mechanism leads to resonating structures with a moderate Q factor. We report here on gold nanoparticle enhancement of the gain in dyes/nanoparticles/polymer film random lasers. Importantly, we demonstrate a lower threshold for lasing and a stronger output intensity, which depend on the nanoparticle (NP) size. All these features can be explained by recent theoretical models suggesting that the random lasing properties are dominated by an enhanced photon scattering mechanism induced by the surface-plasmons. At the end of my talk, if time allows, I shall demonstrate how surface plasmon resonance techniques allow bio-detection of glucose in life cells, blood and water.