Figure 1. Design and fabrication of metamaterial absorber.

(a) Schematic unit cell cross-section of a metamaterial IR absorber consisting of a 50-nm Au micro-ribbon on a thick Au film separated by a 30-nm MgF₂ gap layer. (b) Photograph of the fabricated metamaterial with a total area of 26 × 26 mm² and (c) its SEM image, revealing that the width, w, and unit cell dimension, Λ, were 1.5 μm and 3 μm, respectively. (d) Experimental setup of FT-IR reflection measurement by changing the incident angle, θ, of the p-polarized light.