Optical properties of ultrafine line and space polymeric nanogratings coated with metal and metal–dielectric–metal thin films

Noble metal and metal–dielectric–metal ultrathin films were deposited on the surfaces of ultrafine polymeric nanogratings, which were fabricated using nanoimprint lithography. Experimental results showed dramatic differences of the surface morphologies for single metal and triple metal–dielectric–metal films deposited on flat and corrugated polymeric surfaces. The effect of the surface morphology on the optical properties was hence investigated and analyzed under linearly polarized light. The surface plasmon resonances of single metal and triple metal–dielectric–metal films deposited on polymeric nanograting surfaces were also characterized based on the Kretschmann prism-coupling method. The single metal and triple metal–dielectric–metal films deposited on polymeric nanograting surfaces are important for the study of photon–plasmon interactions (i.e. couplings and conversions) at the interfaces between a nanograting and metal films.