Dual‐Band Tungsten‐Based Infrared Metamaterial Absorber for MWIR and LWIR Regions

ABSTRACT A highly efficient absorber operating in the mid‐wavelength infrared (MWIR) and long‐wavelength infrared (LWIR) regions is important for a wide range of applications, particularly in stealth and thermal camouflage technologies. In this work, we propose a simple and cost‐effective tri‐layer metamaterial absorber made of tungsten (W), zinc oxide (ZnO), and indium tin oxide (ITO). The structure consists of a periodic array of tungsten (W) circular disks on the top layer, zinc oxide (ZnO) as a dielectric spacer layer in the middle, and an indium tin oxide (ITO) reflective layer at the bottom. This W/ZnO/ITO configuration achieves strong absorption within the 3–6 µm (MWIR) and 9–12 µm (LWIR) spectral bands, with peak absorptance 95% at ∼4 µm and ∼98% at ∼10.6 µm, respectively. The high absorption efficiency is attributed to optimal impedance matching and the excitation of localized plasmonic resonances. Furthermore, the absorption characteristics are systematically analyzed by varying structural parameters to ensure design robustness and tunability. Due to the thermal stability of tungsten and the broadband absorption performance, the proposed metamaterial absorber is a promising candidate for applications in stealth technology, thermal imaging suppression, infrared sensing, and energy harvesting.