Cai Haoyuan, Sun Yi, Wang Xiaoping, Zhan Shuyue
Opt Express. 2020 May 11;28(10):15347-15359. doi: 10.1364/OE.393423.
An ultra-broadband metamaterial absorber, consisting of 2D SiO-Ti square bilayer grating on SiO film and Ti substrate, is proposed and designed by rigorous coupled wave analysis (RCWA) and genetic algorithm (GA) methods. The optimized structure shows an average absorption of 98.3% in the wavelength range of 300 nm to 2100 nm. Moreover, the metamaterial absorber is polarization-independent and also insensitive to incidence angle for both TM- and TE-polarized waves. The physical mechanisms responsible for nearly perfect broadband absorption, including the Wood's anomaly (WA), cavity resonance (CR), surface plasmon polaritons (SPPs) and the resonance of magnetic polaritons (MPs), have been analyzed clearly by finite-difference time-domain (FDTD) method and the inductor-capacitor (LC) circuit model. Overall, the proposed metamaterial absorber is a promising candidate in solar applications.
提出并设计了一种由SiO薄膜和Ti衬底上的二维SiO-Ti方形双层光栅组成的超宽带超材料吸收体，采用严格耦合波分析（RCWA）和遗传算法（GA）方法进行设计。优化后的结构在300nm至2100nm波长范围内的平均吸收率为98.3%。此外，该超材料吸收体与偏振无关，对TM波和TE波的入射角也不敏感。通过时域有限差分（FDTD）方法和电感-电容（LC）电路模型，清楚地分析了实现近乎完美宽带吸收的物理机制，包括伍德异常（WA）、腔共振（CR）、表面等离激元极化激元（SPP）和磁极化激元（MP）的共振。总体而言，所提出的超材料吸收体在太阳能应用中是一个很有前景的候选方案。
