Random laser action in dielectric-metal-dielectric surface plasmon waveguides

A dielectric-metal-dielectric (DMD) surface plasmon (SP) waveguide, in which the top and bottom dielectric layers are incorporated with scatters and optical gain, respectively, was realized to support random lasing action. For the DMD waveguide under 532 nm optical excitation, sharp peaks at around 590 nm were observed from the edge of the top dielectric layer. Furthermore, the number of sharp peaks increases with the pump intensity. The dependence of lasing threshold on the excitation area also agrees with the random laser theory. Hence, it is verified that the SP waves, which supported inside the DMD waveguide, exhibit random lasing action. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3274042]