Using Surface Plasmon Propagation through Nanostructures for Chemical and Biological Sensing

Surface plasmon waves (SP) are electromagnetic waves that propagate at the interface between a metal such as gold or silver and a dielectric. In a manner similar to the propagation of photons through a Fabry-Perot filter, the propagation of SP can be blocked by periodic nanostructures on the surface. This phenomenon can be described with a band gap in the SP dispersion relation. By taking advantage of this property, we developed a new chemical and biological sensor. Compared to traditional Surface Plasmon Resonance (SPR) sensing, our sensor does not require precise control or measurement of the transverse momentum of the excitation light. Therefore, for comparable sensitivity, the Surface Plasmon Band Gap sensor will be more easily implemented in a compact format. We present here the numerical simulations and the first optical measurements that demonstrate the validity of our approach.