Surface plasmons leaky radiation of the flat metal

摘要

Surface plasmons have been widely investigated in many fields due to the unique property. ATR (attenuated total-reflection) is the common method to excite surface plasmons. We derive the Fano-type analysis to present the reflection spectrum of ATR configuration derived from the three-layer Fresnel reflection equation, which are asymmetric curves resulted from interference between direct reflectance and surface plasmons leaky radiation. In the fitting progress, we obtain the relationship between surface plasmons leaky radiation and metal thickness. When the metal thickness is greater than 25nm, surface plasmons leaky radiation rate is less than 0.07. We also compare the ATR and grating coupler excitement mechanism, which provide a reference to evaluate their application.