Efficient Circular Polarizer Using A Two-Layer Nanoparticle Dimer Array With Designed Chirality

Using a two-layer metal nanoparticle dimer array, we numerically show that the array can act as an efficient circular polarizer. Linearly polarized incident light can be completely split into right and left circularly polarized light. The simulation results show that the efficiency of the polarizer depends on the size of the nanoparticles, the gap distance between the two particles in the dimers, the distance between the two layers, and the relative orientation between the dimer axes in the two layers. The periodic distance between two neighboring dimers in one layer is also a crucial factor affecting the splitting efficiency. The simulation results demonstrate a simple route of using plasmonic nanomaterials for designing efficient circular polarizers.