提出了一种基于金属环结构的太赫兹超窄带吸收器, 其结构单元为典型的金属-介质-金属结构, 顶层金属图案由封闭金属环和四开口金属环组成, 底层为连续金属板。对该吸收器的窄带吸收原理和吸收峰频率处吸收器结构的表面电流分布进行了研究。结果表明：该吸收器在1.7682THz处存在狭窄的吸收峰, 吸收率为99.8%, 相对于该谐振频率的半高全宽为0.51%, 而且对x和y极化入射波具有极化不敏感。该吸收器具有结构简单、易于加工的优点, 在生物传感、窄带热辐射和光电探测等领域有着重要的潜在应用价值。

A terahertz ultra-narrow band absorber based on metal ring structure is proposed. The unit cell of the absorber adopts typical metal-dielectric-metal structure, the top metal pattern consists of closed metal ring and four-split metal ring, and the bottom layer is continuous metal plate. The narrow band absorption principle of the absorber and the surface current distribution of the absorber structure at the absorption peak frequency were studied. The research shows that the absorber possesses a narrow absorption peak at 1.7682THz, the absorption is 99.8%, the full width at half maximum relative to the resonance frequency is 0.51%, and it is polarization insensitive to the polarization of x and y incident waves. The absorber characterized by simple structure and easy processing has potential application value in bio-sensing, narrow band thermal radiation and photoelectric detection.