Collaborative Research: Programmable THz Devices Enabled by High-Performance Optical Spatial Modulation for Advanced Imaging and Adaptive Communications

该项目将研究和开发一种基于台面阵列的高性能波前空间调制的新方法，以有效地产生使用传统方法无法实现的可调谐和可重构的准光THz分量。利用所提出的方法和组件，将进一步探索和演示三种先进的太赫兹成像体系结构和自适应无线通信链路。太赫兹区域的成像和通信都是重要的技术领域，将产生巨大的社会效益。例如，通过可重新配置的编码孔径实现的亚波长分辨率的高速太赫兹近场成像可以在化学传感、医学成像和癌症诊断中得到应用。实时超灵敏被动成像可用于天文观测和快速安检(如检测人体微弱黑体辐射、环境场景)。使用可调滤光片的太赫兹光谱成像将使先进的生物传感以及物质/材料识别和检测成为可能。最后，即将展示的自适应THz无线通信链路(通过可调谐滤波器和波束控制/成形天线实现)将极大地支持当前开发先进THz设备、电路和系统的努力，并可能对5G蜂窝网络、安全军事和国防链路、物联网、芯片到芯片互联、4K电视信号广播和多媒体下载产生深远影响。该项目还为学生提供了重要的教育机会。该专业的研究生将全面接触半导体物理、电磁波传播、高级成像、太赫兹系统设计和测试流程、无线通信，从单一设备到元件/电路/系统级别。圣母大学和俄勒冈州立大学之间将启动一项合作教育活动，提供远程研究生级别的讲座。本科生将通过暑期和荣誉论文研究参与其中。PIS将为代表人数不足的群体的学生提供建议和指导。最后，该项目还将促进当地初中和高中的科学和工程教育。该方案的目的是探索和展示一种基于台面阵列方法的新型高性能光THz空间调制技术，以有效地实现先进的THz成像和自适应THz无线通信系统中所需的可调和可重构的准光器件。这项技术将提供亚波长空间分辨率、高于100分贝的调制深度、更高的速度，并允许为以高太赫兹频率运行的多功能设备和组件虚拟生成高分辨率照片定义图案。以台面阵列技术为平台，研究和论证了性能和通用性远远超过传统方法的可调谐/可重构太赫兹准光学器件，包括成像编码掩模、波控和形成天线以及通用可调谐滤光器。在上述研究的基础上，将开发一种紧凑、可动态编程的太赫兹准光学器件/组件模块。通过采用积木等模块，将展示三种先进的THz成像体系结构：1)亚波长分辨率的高速THz近场成像；2)实时超灵敏无源THz成像；3)光谱分辨THz成像和原型自适应THz无线通信链路。该项目将涉及半导体物理、太赫兹科学与技术、成像理论、无线通信和高频测试与表征，以实现和展示所提出的用于可调/可重构太赫兹准光学器件的新方法。如果成功，该项目将建立一个独特而强大的技术平台，用于开发使用任何其他传统方法无法实现的可调谐和可重新配置的准光THz器件。

This project will investigate and develop a novel approach based on high-performance wavefront spatial modulation using mesa arrays for efficiently generating tunable and reconfigurable quasi-optical THz components that could not be realized using conventional approaches. Using the proposed approach and components, three advanced THz imaging architectures and adaptive wireless communication links will be further explored and demonstrated. Both imaging and communication at THz region are important technological areas that will generate significant benefit to the society. For example, high-speed THz near-field imaging with subwavelength resolution enabled by reconfigurable coded-apertures may find applications in chemical sensing, medical imaging, and cancer diagnostics. Real-time ultrasensitive passive imaging can be used in astronomy observation and rapid security screening (e.g., detect weak blackbody emission from the human body, environmental scenes). THz spectroscopic imaging using tunable filters will enable advanced biological sensing, and substance/material identification and detection. Finally, adaptive THz wireless communication links (enabled by tunable filters and beam-steering/forming antennas) to be demonstrated will significantly bolster current efforts to develop advanced THz devices, circuits and systems, and may have profound impact on 5G cellular networks, secure military and defense links, the internet of things, chip-to-chip interconnection, 4K TV signal broadcasting, and multi-medium downloading. The project also provides significant educational opportunities for students. The graduate students in this program will be exposed to the full scope of semiconductor physics, electromagnetic wave propagation, advanced imaging, THz system design and testing process, wireless communication, from a single device to the component/circuit/system level. A cooperative education activity will be initiated between the University of Notre Dame and Oregon State University with remote graduate-level lectures. Undergraduate students will be involved through summer and honors thesis research. The PIs will advise and mentor students from underrepresented groups. Finally, this project will also promote science and engineering education among local middle- and high-schools. The objective of this proposal is to explore and demonstrate a novel high-performance optical THz spatial modulation technology based on a mesa-array approach for efficiently achieving tunable and reconfigurable quasi-optical devices that are required in advanced THz imaging and adaptive THz wireless communication systems. This technology would offer sub-wavelength spatial resolution, higher than 100 dB modulation depth, higher speed, and permit high-resolution photo-defined patterns to be virtually generated for devices and components operated at high THz frequencies with multi-functionality. Using this mesa-array technology as a platform, tunable/reconfigurable THz quasi-optical devices, including imaging coded masks, beam steering and forming antennas and universally-tunable filters, with performance and versatility far beyond those realized by conventional approaches will be investigated and demonstrated. Acting on the above investigation, a compact, dynamically programmable THz quasi-optical device/component module will be developed. By employing such modules as building blocks, three advanced THz imaging architectures 1) high-speed THz near-field imaging with sub-wavelength resolution, 2) real-time ultra-sensitive passive THz imaging, and 3) spectrally-resolved THz imaging and prototype adaptive THz wireless communication links will be demonstrated. The project will involve semiconductor physics, THz science and technology, imaging theory, wireless communication, and high-frequency testing and characterization to implement and demonstrate the proposed novel approach for tunable/reconfigurable THz quasi-optical devices. If successful, the project will establish a unique and powerful technology platform for developing tunable and reconfigurable quasi-optical THz devices that cannot be realized using any other conventional approaches.