太赫兹波段超材料的制作、设计及应用

Fabrication,design and application of THz metamaterials

本文从制作方法、结构设计和材料选择几方面综述了超材料在太赫兹波段的电磁响应特性和潜在应用。首先,介绍了获得不同维度、具有特异电磁响应以及结构可调超材料的各种微加工制作方法,进而分析和讨论了超材料的电磁响应特性。文中指出,结构设计可以控制超材料的电磁响应特性,如各向异性、双各向异性、偏振调制、多频响应、宽带响应、不对称透射、旋光性和超吸收等。超材料的电磁响应依赖于周围微环境的介电性质,因而可用于制作对环境敏感的传感器件。此外,电光、磁光、相变、温度敏感等功能材料的引入可以获得光场、电场、磁场、温度等主动控制的太赫兹功能器件。最后,简单介绍了超材料在太赫兹波段进一步发展所面临的机遇和挑战。

In this paper, the electromagnetic responses and potential applications of THz metamaterials are re- viewed through the focus on fabrication, unit structure design, and material selection, respectively. It de- scribes different kinds of fabrication technologies for obtaining metamaterials with special electromagnetic re- sponses such as magnetic resonance and reconfigurable tunability, which is helpful for further understanding of electromagnetic resonances in metamaterials. The paper analyzes the electromagnetic response characteristics in detail and points out that the unit structure design can be used to obtain desired electromagnetic characteris- tics, such as anisotropy, bianisotropy, polarization modulation, multiband response, broadband response, asymmetric transmission, optical activity, and perfect absorption, etc. The dependence of electromagnetic re- sponses upon surrounding dielectrics can be used not only to control resonant frequency by a proper substrate selection, but also for sensing applications. Furthermore, the introduction of functional materials with control- lable dielectric properties by external optical field, electrical field, magnetic field and temperature has the po- tential to achieve tunable metamaterials, which is highly desirable for THz functional devices. Finally, the op- portunities and challenges for further developments of THz metamaterials are briefly introduced.