Tunable Optical Filter Based on Gold and Silver Double-Sided Gratings and its Application as Plasmonic Sensor

Doubled-sided grating structures including two identical single-layered metal gratings separated by a dielectric layer exhibit enhanced optical transmission in the visible region for transverse magnetic polarized light. The maximum transmission (71%) is attributed to a resonance of magnetic polaritons while the minimum one (5%) is found to be caused by surface plasmons between metal and dielectric layers. The transmission resonance of the grating structures is analyzed by varying their geometrical parameters and materials in order to evaluate different potential applications such as tunable optical filters, polarizers, and self-suspended-type plasmonic sensors.