A tunable dual-band metamaterial absorber composed of a gold square ring and a metal film separated by a strontium titanate dielectric is investigated. Two resonance peaks at frequencies 0.162 THz and 0.329 THz with over 99% absorbance are realized at room temperature. The maximum ratio between the lattice constant and the resonance wavelength is approximately 8.2%, which is much smaller than that of the formerly reported absorber. When the temperature changes from 150 K to 350 K, the two resonance absorption peaks at approximately 66.2% and 67.8% of the modulation depths are obtained. The effective impedance method and the LC equivalent circuit modelling are used to analyze the absorption mechanism of the proposed absorber. The proposed absorber is not affected by the change in polarization angles at normal incidence. The proposed structure adopts a single patterned square ring, which can be manufactured easily, and extended to other frequencies in applications such as biosensors, monitoring and imaging.

研究了一种由金方环和由钛酸锶电介质隔开的金属膜组成的可调双波段超材料吸收器。在室温下实现了 0.162 THz 和 0.329 THz 频率处的两个共振峰，吸光度超过 99%。晶格常数与共振波长之间的最大比率约为 8.2%，远小于先前报道的吸收剂。当温度从 150 K 变化到 350 K 时，在大约 66.2% 和 67.8% 的调制深度处获得了两个共振吸收峰。有效阻抗法和LC等效电路模型用于分析所提出的吸收器的吸收机制。建议的吸收器不受垂直入射时偏振角变化的影响。所提出的结构采用单一图案的方形环，易于制造，并在生物传感器、监测和成像等应用中扩展到其他频率。