Polarization insensitive transmission enhanced by staggered metal disk array

The current consensus is exploring and optimizing the sensing performance of plasmonic transmission structure. The theory used is always trying to reduce the size of the structure, enhance the transmission efficiency, and improve the sensitivity. Here the polarization insensitive transmission and refractive index sensing performance enhanced by staggered metal disk array are investigated at infrared regime. With the metal disks being periodically staggered on both sides of a dielectric layer, there is a great improvement of the transmission efficiency at a specific operating wavelength. Compared with the extraordinary optical transmission on one-dimensional gratings, it is found that the transmission phenomenon is insensitive to the polarization of the incident light. Moreover, the sensing performances at each mode peak are enhanced by the staggered design, and the highest sensitivity reaches more than 5000 nm per refractive index unit (RIU). This work is beneficial for biosensing and extraordinary optical transmission research.