We propose an ultra-broadband metamaterial absorber composed of a four-headed arrow-shaped top layer and titanium-bottom film spaced by a dielectric layer. The absorber attains an average absorption of 95.21% ranging from 300 to 2000 nm, and the peak absorptivity reaches up to 99.9%. The synergy of surface plasmon resonances, cavity modes, and lightning-rod effects lead to the ultra-broadband perfect absorption. We also demonstrate the proposed absorber is insensitive for both transverse electric and transverse magnetic polarization and can retain 90% absorption at a larger incident angle. The proposed ultra-broadband absorber holds promising potential in solar cells, optical imaging, polarization detectors, and other large-area applications.

我们提出了一种超宽带超材料吸收体，该吸收体由四头箭头形顶层和由介电层隔开的钛底膜组成。该吸收剂在300至2000 nm范围内的平均吸收率为95.21％，峰值吸收率高达99.9％。表面等离振子共振，腔模和避雷针效应的协同作用导致超宽带完美吸收。我们还证明了所提出的吸收体对横向电极化和横向磁极化均不敏感，并且在较大的入射角下可以保持90％的吸收率。拟议中的超宽带吸收器在太阳能电池，光学成像，偏振检测器和其他大面积应用中具有广阔的发展潜力。