金属-电介质微盘阵列红外吸收器的光学特性分析

Analysis of Optical Properties of Metal-Dielectric Microplate Array Infrared Absorber

根据亚波长微结构的异常光谱特性,提出了一种"圆形铝盘-圆形SiO_2盘-铝衬底"的二维周期性微结构可调谐红外吸波器.利用有限元算法对其红外光谱反射性质进行了数值模拟,发现该结构对入射的TE或TM光偏振态、在0°~60°大入射角范围内具有良好的吸波效果,共振波长调谐范围4~11μm.用局域等离子体激元共振理论解释了红外吸波机理,证明了所提出的多层微盘结构具有更宽的调谐特性和更好的吸收效率.

A reflective-type infrared filter is proposed based on a two-dimensional periodic microstructure of circular aluminum disc-circular silica disc-aluminum substrate.Its infrared spectral reflectance is numerically simulated by finite element method.The simulated results show that this micro-structure exhibits excellent spectral filtering over 4~11μm spectral range which is tunable,insensitive to TE or TM polarization and incident angles over 0 to 60°.The extraordinary infrared reflectance is deciphered with the plasmon polariton resonance theory,upon which a multilayered nanoring structure is proposed for further tuning to longer wavelengths and better absorption efficiency.