Sinusoidal plasmonic crystals for bio-detection sensors

Corrugated gratings coated with thin films of noble metals have been recognized to be useful substrates for bio-detection by means of the excitation of surface plasmon polaritons (SPP). These substrates show superior performances in terms both of detection limit and of simplicity of detection configuration compared to the classical Kretschmann SPP. A 1D sinusoidal corrugation of the metal-air interface has been fabricated by means of laser interference lithography and metal evaporation. In this paper we report progress in the optimization of the sinusoidal grating surface profile. The quality of the fabricated samples has been proved by the good agreement between experimental and simulated results.