MIM structures were defined on a mirror-polished Si wafer substrate surface by first depositing a 5 nm Cr adhesion layer and 200 nm Au reflector metal films by thermal evaporation. Then, either 5 nm or 50 nm of Cr and 100, 150, 200 nm of SiO 2 were deposited using electron beam (EB)-evaporation. Electron beam lithography (EBL) was used to define periodic nanodisk patterns with individual feature diameters ranging form 600 nm to 4000 nm over 1 × 1 mm 2 areas in a spin-coated ZEP520A positive tone resist. Pattern development was again followed by thermal evaporation deposition of 5 nm or 50 nm thickness Cr adhesion/absorber film, followed by 50 nm thickness of Au. Then, resist lift-off was performed using a heated organic solvent, N-Methyl-2-pyrolidone (NMP) at 100 • C, until a metal layer deposited over the resist fully removed. Lastly, MIM metasurface samples were washed in acetone and methanol and blow-dried in air.