Ultra-broadband metamaterial absorber for infrared transparency window of the atmosphere

Publication date: Available online 2 October 2019Source: Physics Letters AAuthor(s): Ling Li, Hongjie Chen, Zhengwei Xie, Weidong Chen, Wenpeng Zhang, Wuming Liu, Ling LiAbstractThe broadband absorber at the wavelength range from 8 to 13 μm has attracted much attention because this range is exactly the infrared transparency window of the atmosphere. In this Letter, we propose a new structure of ultra-broadband absorber, which is composed of a periodic array of single-sized titanium (Ti) patches and a sandwich (Ti/SiO2/Ti) plane. In the infrared transparency window of the atmosphere, the structure proposed can achieve nearly perfect absorption with the maximal absorptivity up to 99% for the wavelength range from 9.77 to 10.69 μm, and a high average absorptivity of 96.7% from 8 to 13 μm. The strongly localized electric field, at the interface of the top thin Ti film and the dielectric spacer of sandwich plane, leads to the ultra-broadband high absorption. In addition, this structure demonstrates the insensitivity of polarization and oblique angle. This metamaterial absorber with high performances in both bandwidth and absorptivity shows a promising prospect in applications such as thermal emitters, thermal coolers, and infrared sensors.

Source: Physics Letters A - October 3, 2019 Category: Physics Source Type: research