EMISSION ENHANCEMENT CHARACTERISTICS OF OXAZINE IN PMMA MATRIX INFLUENCED BY SURFACE PLASMON POLARITON INDUCED ON SINUSOIDAL SILVER GRATING

Abstract

We present the result of an experimental study on the photoluminescence of a thin layer of oxazine molecules doped into the poly(methyl methacrylate) (PMMA) matrix which is coated on top of sinusoidal silver grating. The surface plasmon polaritons that occur on the metallic grating surface were excited by a He-Ne laser of 633 nm wavelength. The effect of the grating was investigated by angle-resolved reflection and emission spectroscopy performed on the thin film samples with and without the grating. Incident light of both s- and p-polarizations were considered in this experiment and the measurement was performed in the reflection and the photoluminescence modes as well. The results exhibit remarkable resonant effect of photoluminescence enhancement over those observed from the sample with planar silver coating for both incident light polarizations. The much larger enhancement factor of ~50.0 found for the case of p-polarized light can be attributed to the combined contributions of surface plasmon polariton enhanced absorption of excitation light and the resonant coupling between the SPP and the fluorophore, while only the latter was operating in the case of s-polarized incident light which showed a smaller enhancement factor of 6.0.