基于超薄结构人工表面等离激元的太赫兹传感研究

Terahertz sensing technology has wide applications on defense and civil technologies for high-sensitivity detection of explosives, hazardous chemicals, biomedicine and food safety. However, the development of high-sensitivity Terahertz sensing is always limited by the lack of miniaturized high power Terahertz sources and room temperature high-performance detectors. In order to solve this problem, we utilize the advanced theory and technology from high-sensitivity surface plasmon sensing in nano-optics, combine the properties and advantages of Terahertz spoof surface plasmons, and propose a design of Terahertz sensor based on spoof surface plamons of an ultrathin structure, which uses a gap spoof surface plasmon mode to reach high sensitivity. Based on the specificity for various detected samples, we also propose a kind of smart and reconfigurable sensing scheme in room temperature based on metallic metamaterials. In view of these design concepts, we adopt microfabrication, microfluidic channels, micromechanics control and terahertz time-domain spectroscopy in order to achieve a smart spoof surface plasmon Terahertz sensing system based on an ultratin structure. This project will be gradually carried out by physical modeling, computer simulation, fabrication, characterization and measurement, and finally achieve high-sensitivity detection of explosives and biomedicine samples.

在国防和民用科技上，太赫兹传感技术对于爆炸物、危化品、生物医学、食品安全等相关的高灵敏度检测具有广阔的应用前景。然而，高灵敏太赫兹传感技术的发展一直受制于小型化高功率太赫兹源和室温高性能探测器技术匮乏的瓶颈问题。针对这一问题，我们借鉴纳米光学高灵敏表面等离激元传感的先进理论和技术，结合太赫兹波段人工表面等离激元自身的特点和优势，提出一种超薄结构的人工表面等离激元太赫兹传感器设计，利用缝隙模式人工表面等离激元达到高灵敏度传感的目的。针对不同被探测样品太赫兹响应的特异性，我们还提出一种常温下基于金属超构材料的智能化可重构传感机制。基于这些设计理念，通过微细加工、微流通道、微机械控制和太赫兹时域光谱等技术手段实现智能超薄结构人工表面等离激元太赫兹传感系统。本项目将通过物理建模、计算机模拟、制备、表征和测试研究逐步开展，最终实现对爆炸物、生物医学等样品的高灵敏检测。

基于太赫兹分子指纹光谱传感的痕量检测由于免标记、非破坏、特异性识别等优点，使其在爆炸物、危化品、生物样品等检测领域具有极大潜力。当前，太赫兹痕量分子指纹传感主要面临的挑战为痕量样品与太赫兹波长之间存在巨大的尺寸差异，造成太赫兹波与痕量样品之间的相互作用非常微弱。近几年来，众多研究者一直在寻求用具有近场局域和光场增强的超构表面来克服这一挑战，但单一谐振增强的特点不适用于在宽频段内具有丰富指纹特征的痕量样品太赫兹传感。本研究基于低损耗超构表面，基于多路信号复用调控方案，进行太赫兹宽带增强传感研究。多路信号复用与超构表面谐振增强效应的结合，不仅能在宽频带内显著增强痕量样品的太赫兹吸收，并且能够针对不同频段指纹区的痕量样品灵活调控传感工作范围。本研究将聚焦于太赫兹宽带增强传感器件的设计和优化，痕量样品的均匀共形装载与表征，器件的制备和痕量样品检测等工作。本项目的研究工作成果将为通用化太赫兹痕量分子指纹传感奠定重要的理论与实验基础。