基于波导结构的集成式太赫兹共焦成像系统

Integrated terahertz confocal imaging system based on THz waveguides

太赫兹成像技术广泛应用于无损检测、生物医学、国防安全等领域。介绍了一种基于波导结构的太赫兹共焦成像系统。首先,搭建了一套集成的连续太赫兹波反射式成像系统,用金属刀片验证成像效果,结果表明该系统能实现接近波长量级(3 mm)的空间分辨率;其次,对混凝土进行太赫兹成像,能够清晰地呈现出混凝土中的钢筋结构。在此基础上,通过在太赫兹探测器端引入金属针孔,构建太赫兹共焦成像系统,并将其用于泡沫中两根钢钉的空间分布检测,实现了样品的三维信息提取,准确测得两钢钉的空间距离(24 mm)。结果表明:文中提出的基于波导结构的太赫兹共焦成像系统具有结构紧凑,便携集成等优势,特别适合于实际工程化应用。

Terahertz(THz)imaging technology provides perspective applications in non-destructive inspection,medical diagnostic and national defense.An integrated terahertz confocal imaging system based on THz waveguides was reported in this paper.Firstly,a reflective THz imaging of a metal razor blade with lateral resolution close to wavelength(3 mm)was acquired.Then,a reinforcing metallic bar in concrete was detected effectively,which provided a feasible method to ensure the quality of construction.Further,by introducing a pinhole before the THz detector,a THz confocal imaging system was set up and depth information(24 mm)between two nails inserted in different depths in insulating foam could be extracted,which was three-dimensional information.The results show that the proposed terahertz confocal imaging system based on waveguides structure has the advantages of compact structure and portable integration,which is especially suitable for practical engineering applications.