Collaborative Research: Multiband, Ultrasensitive Terahertz Imaging Receivers Based on Quasi-Optical Balanced Hot-Electron Mixers

这项研究的目的是探索实现并研究在1-3太赫兹频率范围内潜在地提供最高可用外差检测灵敏度的多波段成像接收器系统的性能。该方法是将一对相同的超导热电子测辐射热计(HeBS)集成到一个双极化正弦天线中，形成准光学平衡混频结构。为了进一步降低系统噪声，将集成超导微波混合器用于中频输出。太赫兹多频段/可重构频率选择表面(FSS)也将被探索用于接收器系统。该研究计划包括工作在亚毫米波至太赫兹体制下的原型接收机的详细设计、仿真、开发和实验演示。该项目的智力优势集中在将两个HeBS集成到一个正弦天线中以实现适用于多频段THz探测和成像应用的高性能接收器系统所带来的挑战和机遇。采用准光平衡混频器结构、超导中频混合器集成和多频段/可调谐THzFSS等新方法，实现了超低系统噪声和多频工作。预计在太赫兹器件、电路设计和集成技术方面将取得进展。所获得的见解可能会被转移到其他太赫兹探测和成像技术中。更广泛的影响包括创造新的科学/工程知识，以及对大学教育的贡献。除了太赫兹社区，这项工作还将惠及广泛的科学学科，如天文学、大气物理学、化学/生物传感和医学诊断学。该专业的研究生将接触到从设备到系统级别的整个系统设计过程。本科生将通过暑期和荣誉论文研究参与其中。

The objective of this research is to explore the realization and study the performance of a multiband imaging receiver system that potentially provides the highest available heterodyne detection sensitivity in the frequency range of 1-3 THz. The approach is to integrate a pair of identical superconducting hot-electron bolometers (HEBs) into a dual-polarization sinuous antenna to form a quasi-optical balanced mixer configuration. To further reduce the system noise, a superconducting microwave hybrid will be integrated for IF output. THz multi-band/reconfigurable frequency selective surfaces (FSSs) will also be explored to be employed in the receiver system. The research program consists of detailed design, simulation, development, and experimental demonstration of prototype receivers operating in the sub-millimeterwave through THz regimes. The program's intellectual merit centers on the challenges and opportunities offered by integrating two HEBs into a sinuous antenna to realize a high performance receiver system suitable for multiband THz detection and imaging applications. The ultra-low system noise and multi-frequency operation are achieved by novel approaches of quasi-optical balanced mixer configuration, the integration of superconducting IF hybrids and the utilization of multiband/tunable THz FSSs. Advances in THz devices, circuits design and integration technology are expected. Insights gained may be transferrable to other THz detection and imaging technologies. The broader impacts include both the creation of new scientific/engineering knowledge, as well as contributions to university education. In addition to the THz community, this work will benefit a wide range of science disciplines such as astronomy, atmospheric physics, chemical/biological sensing, and medical diagnostics. The graduate students in this program will be exposed to the full scope of the system design process, from devices to the system level. Undergraduates will be involved through summer and honors thesis research.