Giant electromagnetic field in periodic metal-silicone metasurface and SERS sensors

Anomalous optical response for the metamaterial fabricated from silicon bar resonators is investigated. The resonators are manufactured in form of two-dimensional bars and covered by semicontinuous silver film. The calculations as well as real experiments demonstrate Wood anomalies in visible and near IR spectral ranges associated with excitation of the surface waves in metamaterial by means of diffraction of the incident light on the periodic bars. The multiple metal-dielectric resonances result in much enhanced local electromagnetic fields in-between metal particles placed on the surface of dielectric bars. The resonances can be tuned by varying angle of incidence, polarization, and geometry of the dielectric bars. It opens new venue in R&D SERS substrates including sensors detecting specific substances.