基于超材料的太赫兹波长可调窄带吸波体研究

项目名称： 基于超材料的太赫兹波长可调窄带吸波体研究

项目编号： No.61265005

项目类型： 地区科学基金项目

立项/批准年度： 2013

项目学科： 无线电电子学、电信技术

项目作者： 胡放荣

作者单位： 桂林电子科技大学

项目金额： 48万元

中文摘要： 基于热效应的太赫兹探测器响应频带宽，灵敏度低，不利于进行高灵敏度和高光谱分辨率的探测。最近提出将超材料太赫兹窄带吸波体制作在热效应探测器的接收表面，可提高探测灵敏度和光谱分辨率，但现有超材料吸波体吸收波长不可调，这样会限制探测器工作波长范围和对波长的动态选择能力，最终降低探测效率和信噪比。 本项目主要创新是通过在开口环谐振器的开口中央引入微悬臂梁来构建太赫兹波长可调窄带吸波体，并用静电方式驱动悬臂梁运动来实现吸收波长连续可调。先用时域有限积分方法和阻抗匹配理论研究吸波机理；用传输线理论建立等效电路模型，研究吸收波长的调控参数和调控方法。然后，结合表面微加工工艺研究器件制作方法，其关键技术是采用牺牲层腐蚀技术释放悬臂梁。最后，验证电压对吸收波长的调控行为。本研究可揭示太赫兹波与可动超材料相互作用机理，有助于提高热效应探测器动态选择波长的能力，促进其在高灵敏度、高光谱分辨率探测领域的应用。

中文关键词： 太赫兹；超材料；窄带吸波体；波长可调；微机电系统

英文摘要： Conventional thermally based terahertz (THz) detectors have the characteristic of broadband response and low sensitivity, and therefore, can not be used for high sensitivity and high spectroscopic resolution detection. Recently, a proposed method for this problem is to attach a metamaterial THz narrowband absorber on the absorbing surface of the detector to improve its sensitivity and spectroscopic resolution. However, current metamaterial THz narrowband absorbers can not be tuned, which greatly limits their operating frequency range and their abilities to dynamically select wavelength, and eventually decreases their detection efficiancy and signal-to-noise ratio. The innovation of this project is that it constructs a new type of metamaterial THz tunable narrowband absorber which mainly consists of a split ring resonator (SRR) and a micro-cantilever. The absorbing wavelength can be tuned continuously by micro-cantilever which is electrostatically actuated. Firstly, a finite-integral time-domain (FITD) method and the principle of impedance matching are introduced to study absorption mechanism. Secondly, an equivalent circuit model based on transmission line theory is created to investigate the parameters and means of wavelength modulation. Then, based on a surface micromachining process, the fabrication is studie

英文关键词： terahertz；metamaterials；narrowband absorber；tunable wavelength；microelectromechanical systems