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使用台阵列的高性能波前空间调制的新方法，以有效地产生可调谐和可重构的准光学太赫兹元件，这是使用传统方法无法实现的。利用提出的方法和组件，三种先进的太赫兹成像架构和自适应无线通信链路将进一步探索和演示。太赫兹区域的成像和通信都是重要的技术领域，将产生重大的社会效益。例如，通过可重构编码孔径实现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找到应用。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、环境场景的微弱黑体发射）。使用可调滤波器的太赫兹光谱成像将实现先进的生物传感、物质/材料识别和检测。最后，将展示的自适应太赫兹无线通信链路（由可调谐滤波器和波束导向/形成天线实现）将极大地支持当前开发先进太赫兹设备、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、芯片对芯片互连、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。该专业的研究生将接触到半导体物理，电磁波传播，高级成像，太赫兹系统设计和测试过程，无线通信，从单个设备到组件/电路/系统级别的全部范围。美国圣母大学和俄勒冈州立大学将开展远程研究生授课的合作教育活动。本科生将参与暑期和荣誉论文研究。私人顾问将为来自代表性不足群体的学生提供咨询和指导。最后，该项目还将促进当地初中和高中的科学和工程教育。本提案的目的是探索和展示一种基于台阵方法的新型高性能光学太赫兹空间调制技术，以有效地实现先进太赫兹成像和自适应太赫兹无线通信系统所需的可调谐和可重构准光学器件。该技术将提供亚波长空间分辨率、高于100 dB的调制深度、更高的速度，并允许为在高太赫兹频率下工作的设备和组件虚拟生成高分辨率的照片定义模式，具有多种功能。利用这种台阵技术作为平台，将研究和演示可调谐/可重构太赫兹准光学器件，包括成像编码掩模、波束导向和成形天线以及通用可调谐滤波器，其性能和通用性远远超过传统方法所实现的。基于上述研究，将开发一种紧凑、动态可编程的太赫兹准光器件/组件模块。通过使用这些模块作为构建模块，将演示三种先进的太赫兹成像架构1)高速太赫兹近场亚波长分辨率成像，2)实时超灵敏被动太赫兹成像，以及3)光谱分辨太赫兹成像和原型自适应太赫兹无线通信链路。该项目将涉及半导体物理、太赫兹科学与技术、成像理论、无线通信以及高频测试和表征，以实现和演示拟议的可调谐/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，用于开发可调谐和可重构的准光学太赫兹器件，这是任何其他传统方法都无法实现的。

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.