The 2023 terahertz science and technology roadmap

Terahertz (THz) radiation encompasses a wide spectral range within the electromagnetic spectrum that extends from microwaves to the far infrared (100 GHz-similar to 30 THz). Within its frequency boundaries exist a broad variety of scientific disciplines that have presented, and continue to present, technical challenges to researchers. During the past 50 years, for instance, the demands of the scientific community have substantially evolved and with a need for advanced instrumentation to support radio astronomy, Earth observation, weather forecasting, security imaging, telecommunications, non-destructive device testing and much more. Furthermore, applications have required an emergence of technology from the laboratory environment to production-scale supply and in-the-field deployments ranging from harsh ground-based locations to deep space. In addressing these requirements, the research and development community has advanced related technology and bridged the transition between electronics and photonics that high frequency operation demands. The multidisciplinary nature of THz work was our stimulus for creating the 2017 THz Science and Technology Roadmap (Dhillon et al 2017 J. Phys. D: Appl. Phys. 50 043001). As one might envisage, though, there remains much to explore both scientifically and technically and the field has continued to develop and expand rapidly. It is timely, therefore, to revise our previous roadmap and in this 2023 version we both provide an update on key developments in established technical areas that have important scientific and public benefit, and highlight new and emerging areas that show particular promise. The developments that we describe thus span from fundamental scientific research, such as THz astronomy and the emergent area of THz quantum optics, to highly applied and commercially and societally impactful subjects that include 6G THz communications, medical imaging, and climate monitoring and prediction. Our Roadmap vision draws upon the expertise and perspective of multiple international specialists that together provide an overview of past developments and the likely challenges facing the field of THz science and technology in future decades. The document is written in a form that is accessible to policy makers who wish to gain an overview of the current state of the THz art, and for the non-specialist and curious who wish to understand available technology and challenges. A such, our experts deliver a 'snapshot' introduction to the current status of the field and provide suggestions for exciting future technical development directions. Ultimately, we intend the Roadmap to portray the advantages and benefits of the THz domain and to stimulate further exploration of the field in support of scientific research and commercial realisation.

太赫兹（THz）辐射涵盖了电磁频谱中从微波到远红外（100吉赫兹 - 约30太赫兹）的一个宽光谱范围。在其频率界限内存在着各种各样的学科，这些学科已经并将继续给研究人员带来技术挑战。例如，在过去的50年里，科学界的需求发生了巨大变化，需要先进的仪器来支持射电天文学、地球观测、天气预报、安全成像、电信、无损设备检测等等。此外，应用要求技术从实验室环境走向生产规模供应以及从恶劣的地面位置到深空的实地部署。为了满足这些要求，研发界推动了相关技术的进步，并弥合了高频操作所要求的电子学和光子学之间的过渡。太赫兹工作的多学科性质促使我们制定了2017年太赫兹科学与技术路线图（Dhillon等人，2017年，《物理学报D：应用物理学》50卷，043001页）。然而，正如人们可能设想的那样，在科学和技术方面仍有很多需要探索的地方，并且该领域一直在快速发展和扩大。因此，适时修订我们之前的路线图，在2023年版中，我们既对具有重要科学和公共利益的既定技术领域的关键发展进行了更新，又强调了显示出特别前景的新兴领域。我们所描述的发展涵盖了从基础科学研究，如太赫兹天文学和新兴的太赫兹量子光学领域，到高度应用且对商业和社会有影响的主题，包括6G太赫兹通信、医学成像以及气候监测和预测。我们的路线图愿景借鉴了多位国际专家的专业知识和观点，这些专家共同概述了过去的发展以及太赫兹科学与技术领域在未来几十年可能面临的挑战。该文件的编写形式便于政策制定者了解太赫兹技术的现状，也便于非专业人士和有好奇心的人了解现有技术和挑战。因此，我们的专家对该领域的现状进行了一个“快照”式的介绍，并为令人兴奋的未来技术发展方向提供了建议。最终，我们希望路线图能够描绘出太赫兹领域的优势和益处，并激发对该领域的进一步探索，以支持科学研究和商业实现。