Robust metamaterial-based antireflection coating for surface plasmon polariton resonance

A metasurface antireflection coating (meta-ARC) consisting of a gold disk array (GDA) and a dielectric layer greatly provides the flexibility to reduce the undesired reflection of light at the interface of the incident medium (air) and the surface plasmon polariton (SPP) structures such as a metallic hole array (MHA). Due to the possibility of changing the coupling strength between two different kinds of resonances (in GDA and MHA) caused by fabrication imperfections, we investigate the impacts of resonance coupling to the performance of antireflection by varying the shape of gold disks in meta-ARC and the alignment-shift between GDA and MHA. Simulation results show that (1) the amplitude of transmitted light through meta-ARC (with fabrication-induced shape-variation in GD) and MHA is only changed by small amount as compared to the meta-ARC with ideal-shaped GDs, (2) the transmission through MHA can be improved in the range of 44% (maximally alignment-shifted GDs) up to 83% (perfectly aligned GDs) by suppressing the reflected light owing to the meta-ARC, which indicates that MHA transmission light can be enhanced by more than 44% regardless of any imperfections in the fabrication of GDs while the SPP resonance wavelengths remain invariant in both cases. Our work can pave the way for a robust ARC method, leading to efficiently improving the performance of plasmonic optoelectronic devices when the meta-ARC is integrated.