Grant James P, McCrindle Iain J H, Cumming David R S
School of Engineering, University of Glasgow.
J Vis Exp. 2012 Dec 27(70):50114. doi: 10.3791/50114.
Metamaterials (MM), artificial materials engineered to have properties that may not be found in nature, have been widely explored since the first theoretical(1) and experimental demonstration(2) of their unique properties. MMs can provide a highly controllable electromagnetic response, and to date have been demonstrated in every technologically relevant spectral range including the optical(3), near IR(4), mid IR(5) , THz(6) , mm-wave(7) , microwave(8) and radio(9) bands. Applications include perfect lenses(10), sensors(11), telecommunications(12), invisibility cloaks(13) and filters(14,15). We have recently developed single band(16), dual band(17) and broadband(18) THz metamaterial absorber devices capable of greater than 80% absorption at the resonance peak. The concept of a MM absorber is especially important at THz frequencies where it is difficult to find strong frequency selective THz absorbers(19). In our MM absorber the THz radiation is absorbed in a thickness of ~ λ/20, overcoming the thickness limitation of traditional quarter wavelength absorbers. MM absorbers naturally lend themselves to THz detection applications, such as thermal sensors, and if integrated with suitable THz sources (e.g. QCLs), could lead to compact, highly sensitive, low cost, real time THz imaging systems.
超材料（MM）是一种人工制造的材料，其设计目的是具有自然界中可能不存在的特性。自首次从理论上（1）和实验上（2）证明其独特特性以来，超材料已得到广泛研究。超材料可以提供高度可控的电磁响应，并且迄今为止，已在包括光学（3）、近红外（4）、中红外（5）、太赫兹（6）、毫米波（7）、微波（8）和无线电（9）频段在内的每个与技术相关的光谱范围内得到了验证。其应用包括完美透镜（10）、传感器（11）、电信（12）、隐身斗篷（13）和滤波器（14,15）。我们最近开发了单频段（16）、双频段（17）和宽带（18）太赫兹超材料吸收器装置，在共振峰处的吸收率大于80%。在太赫兹频率下，超材料吸收器的概念尤为重要，因为在该频率下很难找到强频率选择性的太赫兹吸收器（19）。在我们的超材料吸收器中，太赫兹辐射在约λ/20的厚度内被吸收，克服了传统四分之一波长吸收器的厚度限制。超材料吸收器自然适用于太赫兹检测应用，如热传感器，如果与合适的太赫兹源（如量子级联激光器）集成，可能会产生紧凑、高灵敏度、低成本的实时太赫兹成像系统。
