太赫兹实时近场光谱成像研究  

Research on terahertz real-time near-field spectral imaging

作　　者：冯龙呈 杜琛 杨圣新 张彩虹 吴敬波 范克彬 金飚兵 陈健 吴培亨 Feng Long-Cheng;Du Chen;Yang Sheng-Xin;Zhang Cai-Hong;Wu Jing-Bo;Fan Ke-Bin;Jin Biao-Bing;Chen Jian;Wu Pei-Heng(Institute of Superconductor Electronics,School of Electronic Science and Engineering,Nanjing University,Nanjing 210093,China;Purple Mountain Laboratories,Nanjing 211111,China)

机构地区：[1]南京大学电子科学与工程学院超导电子学研究所,南京210093 [2]紫金山实验室,南京211111

出　　处：《物理学报》2022年第16期133-141,共9页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2017YFA0700202,2021YFB2800701);国家自然科学基金(批准号:61871212,92163216,62071217,62027807);中央高校基本科研业务费专项资金;江苏省自然科学基金青年基金项目(批准号:BK20190300)资助的课题。

摘　　要：太赫兹成像在生物医学领域的应用潜力非常大,针对这个需求,本文设计并搭建了一种利用光整流和波前倾斜技术产生强场太赫兹信号以及基于电光探测的实时太赫兹(terahertz,THz)近场光谱成像系统.该系统可以进行大视场THz成像和紧聚焦THz成像的切换使用,为实现系统集成化应用提供了方法.并且由于成像是基于传统的太赫兹时域光谱方法,可以同时获得样品图像光谱幅度和相位信息,光谱分辨率约15 GHz.利用该系统测量研究了一系列微纳加工的样品,对成像系统的性能进行了分析.结果表明,该实时太赫兹近场光谱成像系统在空间分辨率和成像速度上的优越性,在1024×512的像素下,实时成像帧率高达20 f/s(1200张/min).在大视场THz成像下,空间最优分辨率在1.5 THz达λ/4;在紧聚焦THz成像下,空间最优分辨率在0.82 THz达λ/12,这些性能使该系统在生物医学成像、生物效应等方面具有很好的应用场景.In this paper,a real-time near-field high-resolution THz(terahertz,THz) spectral imaging system is designed and built by using optical rectification and wave-front tilting to generate strong-field terahertz signals and based on electro-optical detection.The system can switch between large beam THz imaging and tightfocusing THz imaging,which provides a method for implementing the integrated application of the system.Since the imaging is based on the traditional THz time-domain spectroscopy method,the spectral amplitude and phase information of the sample can be obtained simultaneously.The spectral resolution is about 15 GHz.A series of micromachining samples is measured and studied by using the system,and the performance of the imaging system is analyzed by using the micron structure.The results show the superiority of the real-time high-resolution terahertz spectral imaging system in terms of spatial resolution and imaging speed.The realtime imaging frame rate is up to 20 f/s(1200 frames/min) at 1024 pixel × 512 pixel.In the large-field THz imaging,the optimal spatial resolution reaches λ/4 at 1.5 THz.In the tightly focused THz imaging,the optimal spatial resolution reaches λ/12 at 0.82 THz.These properties make the system suitable for the applications in biomedical imaging,bbological effects and other areas.

关 键 词：太赫兹 近场成像 时域光谱 实时帧率 

分 类 号：R318[医药卫生—生物医学工程] O441.4[医药卫生—基础医学]