EXCITATION OF MOLECULAR FLUORESCENCE VIA SURFACE-PLASMON POLARITONS

The intensity of photoluminescence from a thin layer of laser dye on a metallic grating depends on the polarization and angle of incidence o f the incident beam of light. For an appropriate polarization and angl e of incidence, the beam can resonantly excite surface plasmon polarit ons (SPPs). The dye layer experiences a much enhanced optical field an d so absorbs more energy, and the fluorescence emission intensity is c onsequently enhanced. Experimental results are presented demonstrating an increase by a factor of 9.9 in the fluorescence yield. A novel tec hnique for numerical modelling of the system is presented and, having established the validity of the model, is used to determine how the en hancement depends on the sample parameters.