Resonance modulations of surface plasmons in arbitrary modified Otto and Sarid structures

In this paper, from the Fresnel formulas and pole expansion, we derived app roximation formulas of the reflectivity and resonant split in arbitrary mod ified Otto and Sarid structures. In accordance with the simulation results, we conclude that the modulation sensitivity of the reflectivity versus the gap thickness is larger for a modified Otto structure with a high dielectr ic constant prism and gold film (or silver film). In addition, the modulati on sensitivity of the reflectivity versus the electro-optic dielectric cons tant for a modified Sarid structure with a high dielectric constant prism a nd silver film is much larger than that with other prisms and metal films.