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

University Of Notre Dame, Notre Dame IN

Investigators

Abstract

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.