嵌入式长波红外超宽带完美吸收器  

Long-Wave Infrared Ultra-Broadband Perfect Absorber with Embedded Structure

作　　者：刘坤 刘媛媛[1] 邓芳 朱路[1] 刘唤 Liu Kun;Liu Yuanyuan;Deng Fang;Zhu Lu;Liu Huan(School of Information Engineering,East China Jiaotong University,Nanchang,Jiangxi 330013,China)

机构地区：[1]华东交通大学信息工程学院,江西南昌330013

出　　处：《光学学报》2021年第24期257-266,共10页Acta Optica Sinica

基　　金：国家自然科学基金(61967007,61963016);国防科技重点实验室基金(6142113180101);教育部人文社会科学研究规划基金(18YJAZH150);江西省教育厅科学技术研究重点项目(GJJ170360);江西省重点研发计划(20201BBF61012)。

摘　　要：为了实现长波红外光谱的高吸收,结合阻抗匹配理论和时域有限差分方法设计了一种长波红外超宽带完美吸收器。首先,分析了金属-介质-金属结构的超材料吸收器,该吸收器在7~14μm波段内的平均吸收率大于91%。然后,在金属-介质-金属结构的基础上提出了一种嵌入式结构的超宽带完美吸收器,该吸收器在7~14μm波段具有近乎完美的吸收特性,平均吸收率可达到97.55%,且具有偏振不敏感特性;在入射角度为50°时的平均吸收率仍大于90%(横磁模式下为90.5%、横电模式下为93.7%)。研究结果表明,表面等离子体和法布里-珀罗谐振腔等多种模式的共同作用是获得宽波段完美吸收的主要因素。设计的吸收器在红外光谱内实现了优异吸收,在能量收集、红外传感器等领域具有潜在的应用价值。For high absorption of long-wave infrared spectra,a long-wave infrared ultra-broadband perfect absorber is designed in light of the impedance matching theory by the finite-difference time-domain method in this paper.First,a metamaterial absorber with a metal-insulator-metal structure is analyzed,and the absorber has an average absorptivity of greater than 91% in the range of 7--14 μm.Then,on the basis of the metal-insulator-metal structure,an ultra-broadband perfect absorber with an embedded structure is designed.It has almost perfect absorption characteristics in the range of 7--14 μm with an average absorptivity of over 97.55% and appears to be insensitive to polarization.Its average absorptivity remains over 90%(90.5% in the transverse magnetic mode and 93.7% in the transverse electric mode) when the incident angle is 50°.The research results show that broadband perfect absorption is mainly caused by the combined action of multiple modes such as surface plasmon and the Fabry-Perot resonator.The proposed absorber,with excellent absorption in the range of infrared spectra,holds a promising application prospect in fields such as energy harvesting and infrared sensors.

关 键 词：光学器件 超材料吸收器 红外 宽波段 谐振腔模式 

分 类 号：O431[机械工程—光学工程]