Surface plasmon excitation of amplified spontaneous emission from laser dye molecules embedded in polymer matrix

We report on amplified spontaneous emission (ASE) from a polymer waveguide film containing laser dye molecules (active layer) excited by surface plasmon. The polymer waveguide is deposited on an intermediate polymer layer on top of a metal film on a prism, forming a planar Kretschmann-Raether configuration. The ASE was observed in both a surface plasmon mode and a waveguide mode. In both cases, the photoluminescence was enhanced by a factor of 4 with respect to that which was observed from the same active layer deposited on a bare glass substrate. We show that efficient excitation can be achieved only when the active layer is placed on top of an intermediate polymer layer. The intermediate layer prevents back coupling of light into the prism and possible quenching.