Fluorescence enhancement by surface gratings.

Fluorescence from a layer of Rhodamine 6G (R6G) is observed to be enhanced strongly if a dielectric grating deposited onto a gold film is used as a substrate. The fluorescence enhancement has been studied as a function of the grating periodicity and the angle of incidence of the excitation light. The enhancement mechanism is consistent with excitation of surface-plasmon-polaritons on the metal film surface. The observed phenomenon may be promising in sensing applications.