EAGER: High-performance Optical-phonon-based Terahertz Sources Operating at Room Temperature

EAGER：在室温下运行的基于光学声子的高性能太赫兹源

• 批准号: 1748518
• 负责人: Peter Qiang Liu
• 金额: $ 8.54万
• 依托单位: SUNY at Buffalo
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1748518&HistoricalAwards=false
• 关键词: EAGER; performance; Optical; phonon; based

Title: High-performance Optical-phonon-based Terahertz Sources Operating at Room TemperatureNon-technical DescriptionThe mid-infrared (MIR) to terahertz (THz) spectral range has its unique scientific and technological significance, as it hosts the strongest and fingerprint-like absorption lines of countless molecular species, making it the ideal spectral range for developing sensing technologies with superior selectivity and sensitivity for a broad range of applications. Quantum cascade lasers (QCLs) are currently the preferred light sources for many applications in this spectral range, thanks to their compactness, convenient operation and high output power. However, in the THz region the performance of QCLs is still not sufficient for various real-world applications. THz QCLs have much lower performance than MIR QCLs, and the highest operating temperature of THz QCLs is still limited to ~200K. Furthermore, currently no QCL can operate within the 5 THz to 11THz range. In this exploratory project, we plan to develop a new type of compact, high-performance and room-temperature operating THz sources to cover this "gap" spectral range. The proposed devices are based on an untested but promising new operation principle, and the successful demonstration of such devices will bring transformative impacts to the research field of THz sources and enable various applications. Therefore, the proposed research is suitable for the NSF EAGER program. This project will allow graduate and undergraduate students to actively participate in cutting-edge research, and acquire the knowledge, skills, experiences and broad perspectives necessary for their future leadership in scientific research and technology development on the competitive global stage. Combining research with education and outreach activities will also be a focus of our work, aiming at benefiting students of all age-groups and backgrounds, including those from underrepresented groups.Technical DescriptionThe objective of this project is to systematically explore how to realize a new type of THz sources based on a fundamentally different device operation principle. The device operation principle consists of two key processes: (1) generating optical phonons by resonant inter-subband transitions in multiple-quantum-wells (MQWs), and (2) transferring the energy from the generated optical phonons to resonant THz antennae which then emit photons into free space. As the device operation principle is not sensitive to temperature, such THz sources should operate well at room temperature and above. Designs of the MQWs and the THz antennae will be optimized to make both processes efficient, leading to a high overall energy conversion efficiency which is potentially orders of magnitude higher than that of typical THz QCLs. Moreover, such THz sources have a surface-emitting configuration, so the output power scales up with the device area. The proposed research may also allow us to gain new and/or deeper insights into the interesting and complex physics underlying the interplay between inter-subband transitions in MQWs, optical phonons and electromagnetic resonances of photonic structures. Interactions involving all three excitations have not been systematically studied. A better understanding of the underlying physics will guide us to improve the device design, and may inspire us to pursue new possibilities of more advanced devices.

职务名称：在室温下工作的高性能光学声子太赫兹源非技术描述中红外（MIR）至太赫兹（THz）光谱范围具有独特的科学和技术意义，因为它拥有无数分子物种的最强和指纹状吸收线，使其成为开发传感技术的理想光谱范围，具有上级选择性和灵敏度，适用于广泛的应用。量子级联激光器（QCL）由于其紧凑、操作方便和高输出功率，目前是该光谱范围内许多应用的首选光源。然而，在太赫兹区域，QCL的性能仍然不足以用于各种现实世界的应用。THz QCL的性能远低于MIR QCL，并且THz QCL的最高工作温度仍被限制在~ 200 K。此外，目前没有QCL可以在5 THz至11 THz范围内工作。在这个探索性的项目中，我们计划开发一种新型的紧凑，高性能和室温操作的太赫兹源，以覆盖这个“间隙”的光谱范围。所提出的器件基于未经测试但有前途的新工作原理，此类器件的成功演示将为THz源的研究领域带来变革性的影响，并实现各种应用。因此，建议的研究是适合的NSF EAGER计划。该项目将使研究生和本科生积极参与前沿研究，并获得他们在竞争激烈的全球舞台上的科学研究和技术发展的未来领导所需的知识，技能，经验和广阔的视野。结合研究与教育和推广活动也将是我们的工作重点，旨在使所有年龄组和背景的学生受益，包括那些来自代表性不足的群体。技术说明本项目的目标是系统地探索如何实现一种基于根本不同的设备操作原理的新型THz源。该器件的工作原理包括两个关键过程：（1）通过多量子威尔斯（MQW）中的子带间共振跃迁产生光学声子;（2）将能量从所产生的光学声子转移到共振太赫兹天线，然后将光子发射到自由空间。由于器件工作原理对温度不敏感，因此这种THz源应该在室温及以上温度下工作良好。多量子阱和太赫兹天线的设计将被优化，以使这两个过程都有效，从而导致高的整体能量转换效率，这可能比典型的太赫兹QCL高几个数量级。此外，这种太赫兹源具有表面发射配置，因此输出功率随器件面积而增大。所提出的研究也可以使我们获得新的和/或更深入的见解，有趣的和复杂的物理基础之间的相互作用，在多量子阱，光学声子和电磁共振的光子结构的子带间跃迁。涉及所有三种激励的相互作用尚未得到系统的研究。更好地理解底层物理将指导我们改进设备设计，并可能激励我们追求更先进设备的新可能性。