Broadband long-wave infrared metamaterial absorber based on single-sized cut-wire resonators

Broadband absorption is critical for the applications of metamaterial absorbers. In this work, a broadband long-wave infrared (LWIR) absorber with classical metal-dielectric-metal configuration is numerically demonstrated. The absorber consists of single-sized cut-wire arrays that show broadband and high extinction ratio, attributed to polarization-selective simultaneous excitation of propagated and localized surface plasmon resonances. The average absorption rate of the TM wave reaches 91.7% and 90% of the incident light is absorbed by the resonator in the wavelength range of 7.5-13.251um so that the average extinction ratio in the resonator layer reaches 125. The polarization insensitive broadband absorption can be obtained by a cross resonator which can be treated as a pair of cut-wires perpendicular to each other. Our metamaterial absorber with single-sized resonators shows spatially concentrated broadband absorption and may have promising applications for hot-electron devices, infrared imaging, and thermal detection. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

Automated summary

Broadband long-wave infrared absorber with classical metal-dielectric-metal configuration shows high absorption efficiency and extinction ratio through single-sized cut-wire arrays. Polarization-selective simultaneous excitation of surface plasmon resonances achieves spatial concentration of broadband absorption, while polarization insensitive broadband absorption can be achieved using a cross resonator design. The absorber has potential applications in hot-electron devices, infrared imaging, and thermal detection.