基模磁激元诱导的多带完美吸收

本文提出一种方向不敏感多带吸收的新结构,即结合光学声子色散材料及无色散介电材料,将其作为单一尺寸金属/介质/金属微光栅的介质分离层.在红外大气窗口波段激发了基模磁激元谐振因此导致多频带吸收.基于有限元方法求解了混合结构的吸收率及电磁场分布,并研究了入射角及结构参数的变化对多峰值吸收的影响.考虑到磁激元的本质是由金属光栅...

Multiband Perfect Absorption Induced by Fundamental Magnetic Polaritons

In this paper,a new structure of directional insensitive multiband perfect absorption was proposed,which combined the optical phonon material and the nondispersive dielectric material as the spacer layer of a single sized Metal/Dielectric/Metal micro grating.Multiband absorption induced by magnetic polariton was excited at atmosphere window wavelength band.The spectral absorptivity and electromagnetic field distribution were calculated via finite element method.Effects of incident angle and geometric parameters on absorption were also investigated.Considering that the nature of magnetic polaritons is the reverse current oscillation induced by the lower surface of the metal grating and the upper surface of the metal substrate the multilayer film functions as a dielectric spacer.Effective medium theory(EMT) approximation treatment of multilayer film was performed.LC circuit model with EMT treatment to predict the magnetic polariton resonance condition was verified hereafter.The multiband absorption mechanism proposed in this paper has a bright future in infrared detection,radiative cooling and other fields.