Advanced Terahertz Imaging Systems based on Plasmonic Antenna Arrays

太赫兹波对于医学成像应用是非常有吸引力的，因为与医学成像系统中经常使用的较短波长波相比，太赫兹波的能量非常低，因此它们不会对人体组织造成电离危害。此外，与光波相比，太赫兹波经历的生物组织散射更少，因为它们的波长更长，可以更深入地观察不同的生物组织类型。此外，水的几个吸收线位于太赫兹频谱中，使得太赫兹波非常强大的手段，用于区分具有不同水合水平的组织，这通常用于诊断目的。太赫兹波的这些有吸引力的属性的组合已经引起了对太赫兹成像系统的极大兴趣，并且已经被用于各种医学成像和诊断应用。尽管近年来太赫兹成像系统有了显著的进步，但现有的太赫兹成像系统在其尺寸、图像采集时间、图像分辨率和可检测深度方面具有约束，这限制了其用于各种医学成像和诊断应用的潜在用途的范围。该计划的研究部分将通过开发高性能脉冲太赫兹成像系统来解决现有太赫兹成像系统的一些物理限制，该系统具有在体内成像和诊断应用中的潜在应用。此外，该计划将通过开发新课程，招募和参与本科生以及组织高中研讨会，将研究与教育和推广活动相结合。本研究的目标是开发新一代非接触式太赫兹成像系统，与现有的太赫兹成像技术相比，该系统可提供更大的可探测深度和更快的图像采集速率。为此，一种新的脉冲太赫兹成像系统的基础上的二维阵列的大面积等离子体光电导太赫兹源和检测器兼容的商业内窥镜将实施和实验证明。大面积等离子体光电导源和检测器的使用将增强太赫兹源的输出功率、太赫兹检测器的检测灵敏度和信噪比，从而使得成像系统能够实现显著更大的可检测深度。拟议的工作提出了一个新的角度对太赫兹技术的潜在用途，目前不可能由于现有的太赫兹成像系统的浅的可检测深度和笨重的性质，各种医疗诊断应用。拟议的理论研究将提供一个详细的了解等离子体太赫兹源/探测器操作的基本物理限制，而实验工作将开发适当的设备制造和封装过程兼容的内窥镜系统。

Terahertz waves are very attractive for medical imaging applications since they do not pose an ionization hazard for human tissue, due to their very low energy compared to shorter wavelength waves often used in medical imaging systems. Moreover, terahertz waves experience less scattering from biological tissue compared to optical waves due to their longer wavelengths making it possible to see deeper into different biological tissue types. Additionally, several absorption lines of water lie in the terahertz frequency spectrum, making terahertz waves very powerful means for distinguishing between tissues with different hydration levels that is often useful for diagnostics purposes. The combination of these attractive attributes of terahertz waves has created a great deal of interest in terahertz imaging systems and has been utilized for various medical imaging and diagnostics applications. In spite of a significant advancement in terahertz imaging systems over recent years, existing terahertz imaging systems have constraints in their size, image acquisition time, image resolution, and detectable depth, which has limited the scope of their potential use for various medical imaging and diagnostics applications. The research component of this program will address some of the physical limitations of existing terahertz imaging systems by developing a high-performance pulsed terahertz imaging system with potential application in in-vivo imaging and diagnostics applications. Additionally, this program will integrate research with education and outreach activities by developing new courses, recruitment and involvement of undergraduate students, and organizing high-school seminars. The objective of this research is to develop a new generation of non-contact terahertz imaging systems that offer significantly larger detectable depths and faster image acquisition rates compared to existing terahertz imaging technologies. For this purpose, a novel pulsed terahertz imaging system based on a two-dimensional array of large area plasmonic photoconductive terahertz sources and detectors compatible with a commercial endoscope will be implemented and experimentally demonstrated. The use of large area plasmonic photoconductive sources and detectors will enhance the output power of terahertz sources, detection sensitivity of terahertz detectors, and signal-to-noise ratio, thus enabling significantly larger detectable depths for the imaging system. The proposed work presents a new perspective on the potential use of terahertz technology for various medical diagnostics applications that are not currently possible due to the shallow detectable depth and bulky nature of existing terahertz imaging systems. The proposed theoretical investigation will provide a detailed understanding of the fundamental physical limitations of plasmonic terahertz source/detector operations, while the experimental effort will develop appropriate device fabrication and packaging processes compatible with endoscopy systems.