Surface plasmon-polariton resonances in metal-coated polycarbonate gratings

In this article a study of surface plasmon resonance (SPR) is presented using a diffraction grating to couple light on the dielectric–metal interface. A polycarbonate surface relief gratings obtained from commercially available DVD-R stampers are used as substrates and are subsequently coated with silver and gold thin films (with physical thickness d = 15-25 nm) . The presence of SPR is experimentally verified by the observed resonance peaks in spectral transmittance of TM polarized light. Furthermore, the spectral positions of these peaks are determined for the given film thickness – 510 nm for the Ag layer and 760 nm for the Au layer. The results are compared with previous study of SPR peaks in aluminum thin films.