Figure of Merit for Optimization of Metal–Dielectric Multilayer Lenses

We propose a figure of merit (FoM) to optimize the multilayered metal-dielectric (MD) structure for subwavelength imaging. The proposed FoM accounts both the waveguiding and transmission properties of the multilayered MD structure. We numerically demonstrate that the FoM can be used to find the optimized geometry parameters, as well as the optimized working wavelength. Such a FoM can act as an efficient tool for design and fabrication of the multilayered MD lenses.