CityU_brochure2021_v12_20211215

CONTENT 1 Vision and Mission 1-2 2 愿景和使命 3-4 3 5-8 4 Introduction 9 5 简介 10 11 5.1 Laboratory Members 12 5.2 实验室成员 13 5.3 14 5.4 Honors Received by Laboratory Members 15-16 5.5 实验室成员所获荣誉 17-18 5.6 Selected Research Activities 19 5.7 重点研究活动 20 5.8 Wideband Low-Profile Reconfigurable Transmitarray 21-22 5.9 宽带低剖面可重构的发射阵列 23-24 5.10 Dielectric Resonator Antennas 25-26 5.11 介质谐振天线 27 5.12 Discrete Passive and Active Discrete Metasurfaces for Imaging and Communication 28 5.13 用于成像和通信的无源和有源离散超表面 29 5.14 Wide Impedance- and Gain-Bandwidth THz On-Chip Antenna 30 5.15 宽阻抗和增益带宽的太赫兹片上天线 31-32 5.16 THz Coding Metasurfaces 太赫兹编码超表面 Two-Dimensional (2D) Beam-Scanning THz Bessel Launcher 二维（2D）波束扫描太赫兹贝塞尔发射器 High-Gain Low-Profile Si-Imprinted THz Gaussian Beam Antenna 高增益、低剖面的Si-Imprinted THz高斯光束天线 Silicon-Based Folded Reflectarray Operating at 1 THz 1 THz 的硅基折叠反射阵列 Two-Dimensional Scalable THz Radiator Arrays 二维可扩展的太赫兹辐射器阵列 THz Imaging Using Orthogonal-Polarization Measurements 利用正交偏振测量进行太赫兹成像 Waveguide Amplifier 波导放大器 Integrated Lithium Niobate Electro-Optic Modulator Operating at 300 GHz 300GHz的集成铌酸锂电光调制器 Random Photonic Microwave Signal Generation by Laser Dynamics 基于激光器动力学的随机光子微波信号生成 Terahertz/Millimeter-Wave Hybrid Wireless Networks 太赫兹/毫米波混合无线网络 Nano-Theranostic System 纳米阻断系统 Artificial Visual System of Record-Low Energy Consumption for Next Generation of Artificial Intelligence (AI) 超低耗能的人工视觉系统促进新一代人工智能发展

5.17 High Throughput Platform for the Investigation of Millimeter-Wave Influence on the 33-34 Neural System of Zebrafish Larvae 35-36 5.18 毫米波对斑马鱼幼体神经系统影响的高通量研究平台 37 Design of Luminescent Transition Metal Complexes as Biomolecular Probes 38 5.19 发光的过渡金属复合物设计用作生物分子探针 39 40 5.20 Biomedical Devices and Microsystems with Integrated Sensors and Processing Units 41-42 具有集成传感器和处理单元的生物医学设备和微系统 43-44 6 7 Biomimetic Platforms to Control and Separate Cells and Biomolecules 8 控制和分离细胞和生物分子的仿生平台 9 Core Research Facilities 核心研究设备 Publications and Patents 论文和专利 Student Achievements 学生成就 Laboratory Contact 实验室联系方式

VISION & MISSION 愿景和使命 Vision The State Key Laboratory of Terahertz and Millimeter Waves (City University of Hong Kong) aspires to be a leading labora- tory of its kind in the world. 愿景 太赫兹和毫米波国家重点实验室（香港城市大学）立志成为世界上同行中的领先者。 Mission The State Key Laboratory of Terahertz and Millimeter Waves (City University of Hong Kong) seeks to be a recognized leader nationally and internationally in terahertz and millimeter-wave research. The laboratory is committed to: • Build a world-class laboratory with facilities for modeling, fabrication and testing of millimeter-wave and terahertz; • Recruit and nurture young talents for the advancement and applications of millimeter-wave and terahertz technologies • Conduct high-impact research and promote interdisciplinary research; • Engage with government departments, public bodies, industries, trade associations, universities and other research institutes to promote knowledge transfer for the benefit of the society. 使命 太赫兹和毫米波国家重点实验室（香港城市大学）专注于太赫兹和毫米波研究，致力成为国内外认可的领导者 。 实验室致力于： - 组建一个配备完善毫米波和太赫兹设备以用于模建、制造及测试的世界级实验室。 - 为毫米波和太赫兹技术的发展和应用培养青年人才。 - 开展具前瞻性的研究和促进跨学科研究工作。 - 与政府、公共机构、工商业界、大学和其他研究所合作以促进知识转移，服务社会。 1

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INTRODUCTION 简介 With the approval of the Ministry of Science and Technology, our State Key Laboratory has been renamed to the State Key Laboratory of Terahertz and Millimeter Waves (SKLTMW) since September 2018. Our predecessor, the State Key Labora- tory of Millimeter Waves (SKLMW), Partner Laboratory in the City University of Hong Kong, was established in March 2008 partnering with the State Key Laboratory of Millimeter Waves at Southeast University in Nanjing. City University of Hong Kong (CityU) has a long Materials, devices and design methodologies developed history of excellence in applied electromagnetic for microwave and millimeter-wave regime are not appli- research since the 1980’s when Professor Kai cable to THz. Materials and devices for THz are either Fong Lee, founding head of Department of Elec- not readily available or their properties are not well under- tronic Engineering (now Electrical Engineering) stood yet at the current stage. In addition, THz waves are recruited Professor Kwai Man Luk and Professor non-ionizing and they are suitable for bioimaging and Edward Kai Ning Yung to form a 3-person antenna non-destructive testing. On the other hand, there are research group. Professor Lee is the Dean Emeri- reports saying that exposure to THz radiation can cause tus of School of Engineering at the University of conformable changes in protein molecules and low doses Mississippi and was the awardee of the 2009 IEEE of THz radiation can stimulate cellular proliferation. Antennas and Propagation Society John Daniel Therefore, in addition to electrical engineers, we have Kraus Antenna Award. Professor Luk received the material scientists, chemists and biologists joining our same pr es t igious a w a rd i n 2 0 1 7 . To g e th e r w i th laboratory to conduct interdisciplinary research on THz the addition of the late Professor Kenneth K. Mei science and applications. in 1994, who had a distinguished 32-year career at the University of California at Berkeley and was Professor Chi Hou Chan, director of SKLTMW and a the winner of the 2009 IEEE Electromagnetics recipient of the 2019 Antennas and Propagation Society Award, the CityU research team rapidly rose to Harrington-Mittra Computational Electromagnetics international fame. Award, is currently leading a multidisciplinary team in carrying out a Theme-Based Research Scheme project Professor Luk was the inaugural director of SKLMW. funded by the Hong Kong Research Grants Council on Under his leadership, the research scope of the laborato- the research and development of a compact THz system ry expanded from microwave and millimeter-wave circuit for imaging and spectroscopy. We have already made designs, antenna technologies, and computational tremendous progress in THz antennas, imaging, and electromagnetics into micro- and nano-fabrications, source generation and detection. Our cohesive team of microwave photonics, digital and mobile communications, engineers, biologists, chemists and material scientists multiple-input and multiple-output (MIMO) technologies, would allow us to implement our long-term strategies and sensor networks, nano/micro-electromechanical systems making the lab a leading research center on the research (NEMS/MEMS), and system integrations. More impor- and development of millimeter-wave and THz technolo- tantly, we started building up our research infrastructure gies for 5G, 6G and beyond. for terahertz (THz) science and technology in 2011 at the suggestion of our Advisory Committee. 3

经科技部批准，国家重点实验室自2018年9月更名为太赫兹和毫米波国家重点实验室（SKLTMW）。我们的前身 ，毫米波国家重点实验室(香港城市大学伙伴实验室)（SKLMW），为2008年3月与南京东南大学毫米波国家重点 实验室合作的伙伴实验室。 香港城市大学（城大）在应用电磁学研究方面有着悠久 过去为微波和毫米波系统开发的材料、设备和设计方法 的历史。自20世纪80年代，电子工程学系（现为电机工 并不适用于太赫兹。 用于太赫兹的材料和设备不单没有 程学系）的创系系主任李启方教授招募了陆贵文教授和 可即用的，而现阶段亦对其特性还未充分了解。 此外， 容启宁教授组成了一个三人天线研究小组。 李教授现为 太赫兹波为非电离的电波，适用于生物成像和非破坏性 美国密西西比大学工程学院荣休院长，并为2009年国际 测试。 另一方面，有报告称暴露在太赫兹辐射下会引起 电机暨电子工程师学会天线及传播分会约翰丹尼尔克劳 蛋白质分子结构上的变化及低剂量的太赫兹辐射会刺激 斯天线奖(IEEE Antennas and Propagation Society 细胞增殖。 因此，除了电子工程师之外，还有材料科学 John Daniel Kraus Antenna Award) 得奖者。 陆教授 家、化学家和生物学家加入我们的实验室，进行太赫兹 亦于2017年获得了同样奖项。 接着，梅冠香教授于1994 科学及其应用的跨学科研究。 年加入城大，梅教授拥有在加州大学伯克利分校32年杰 出经验，更是2009年IEEE电磁学奖的得奖者，使城大应 实验室主任暨天线与传播学会Harrington-Mittra计算 用电磁学研究团队的声誉迅速跃升至国际舞台。 电磁学奖(Antennas and Propagation Society Har- rington-Mittra Computational Electromagnetics 陆教授为国家重点实验室的首任主任。 在他的领导下， Award) 得奖者陈志豪教授，目前正带领一个跨学科团队 实验室的研究范围覆盖从微波和毫米波电路设计、天线 开展由香港研究资助局资助的主题研究计划项目，研究 技术和计算电磁学扩展到微纳米制造、微波光子学、数 和开发用于成像和光谱学的紧凑型太赫兹系统。 我们已 码和移动通信、多输入和多输出（MIMO）技术、传感器 在太赫兹天线、成像以及波源生成和检测方面取得了巨 网络、纳米/微机电系统（NEMS/MEMS）和系统集成。 大的进展。 我们由工程师、生物学家、化学家和材料科 更重要的是，采纳了学术委员会的建议后，本实验室在 学家组成的团结团队，使本实验室能够实践我们的长期 2011年开始組建太赫兹（THz）科学技术的研究基础设 战略，使实验室成为研究和开发毫米波和太赫兹技术的 施。 领先研究中心，用于5G、6G和更进一步领域。 4

LABORATORY MEMBER 实验室成员 ADVISORY COMMITTEE | 学术委员会 Quasi-Optical Waveguide Systems Software-Defined Devices CHAIRMAN 主席 Substrate Integrated Circuits(SICs) Professor Ke WU 吴 柯 教授 Theory and Simulation of Material Properties MEMBER 委員 Theory of Advanced materials: Photonic Professor Che Ting CHAN Crystals, Metamaterials and Nano-materials 陈子亭 教授 Professor Chi Hou CHAN Antenna 陈志豪 教授 Computational Electromagnetics Professor Zhi Ning CHEN Terahertz Components and Systems 陈志宁 教授 Professor Wei HONG Antennas and RF 洪 伟 教授 Applied Electromagnetics Dr. Keren LI 李可人 教授 Antennas and RF Technologies Professor Shenggang LIU Microwave Integrated Circuit 刘盛纲 教授 Mobile Communications Professor Kwai Man LUK 陆贵文 教授 Microwave and Antenna Optical Fiber Communication Professor Jun Fa MAO 毛军发 教授 Free Electron Laser Professor Edwin Yue Bun PUN Optics 潘裕斌 教授 Plasma Electronics Relativistic Electronics Professor Lei ZHU 祝 雷 教授 Antenna Design Applied Electromagnetics Microwave and Antenna Measurement Microstrip Antennas, Dielectric Resonator Antennas Computational Electromagnetics Electromagnetic Theory RF and Microwave Circuits Signal Integrity of High-Speed Integrated Circuits Integrated Optics Photonics Technology Nano Photonics Plasmonics Metasurfaces and Metamaterials RF and Microwave Engineering Antenna Technology Applied Electromagnetics 5

DIRECTOR Antenna Computational Electromagnetics Professor Chi Hou CHAN* Terahertz Components and Systems 陈志豪教授 Chair Professor of Electronic Engineering DEPUTY DIRECTOR Antennas Millimeter Wave Technologies Dr Hang WONG Implant Communications 黄衡副教授 Applied Electromagnetics Associate Professor of Department of Small Antenna Electrical Engineering Antenna Measurements Satellite Communications MEMBERS Professor Stella W. PANG Professor Kwai Man LUK*# 彭慧芝教授 陆贵文教授 Chair Professor of Electronic Engineering Chair Professor of Electronic Engineering Nanofabrication Technology Antenna Design Nanoimprint Applied Electromagnetics Biomedical, Microelectronic, Optical, and Microwave and Antenna Measurement Microelectromechanical Devices & Microsystems Microstrip Antennas, Dielectric Resonator Antennas Computational Electromagnetics Professor Din-ping TSAI 蔡定平教授 Professor Kwok Wa LEUNG Chair Professor of Electrical Engineering 梁国华教授 CPrhoafeisrsPor oofeDsespoartmofenEtleofcEtrleocntriocnEicnEgnignineeeerriingg Meta-devices Nano-photonics Antenna Theory and Design Advanced Micro / Nano Fabrication and Design Computational Electromagnetics (Guided Wave Theory, Mobile Communications) * Concurrent member of SKLTMW Advisory Committee # Founding Director 6

MEMBERS Professor Johnny Chung Yin HO 何颂贤教授 Professor Nelson Sze Chun CHAN Professor of Department of Materials Science 陈仕俊教授 and Engineering Professor of Department of Electrical Engineering Synthesis and Characterization of Semiconductor Nano-Materials Microwave Photonics Large-Scale and Heterogeneous Integration of Nonlinear Laser Dynamics Nano-Materials for Flexible and High-Performance Semiconductor Lasers Electronics, Optoelectronics and Energy-Harvesting Optical chaos generation, radio-over-fiber, and photonic microwave generation Dr Rosa Ho Man CHAN 陈皓敏副教授 Professor Kenneth Kam Wing LO Associate Professor of Department of Electrical 罗锦荣教授 Engineering Professor of Department of Chemistry Computational Neuroscience Bioconjugation Neural Prosthesis Biomolecular probes Brain-Computer Interface Imaging reagents Bio-Signal Processing Inorganic photochemistry Photo(cytotoxic) agents Dr Alex Chun Yuen WONG 黄骏弦副教授 Dr Yun Wah LAM 林润华副教授 Associate Professor of Department of Chemistry Associate Professor of Department of Chemistry Synthesis and Application of Nano Materials Proteomics Inorganic and Organometallic Chemistry Spectroscopy Dr Young Jin CHUN Drug Delivery Cosmetic Formulations Assistant Professor of Department of Electrical Engineering Dr Cheng WANG 王骋助理教授 Terahertz and Millimeter Wave Hybrid Network Assistant Professor of Department of Electrical Intelligent Reflecting Surface (IRS) assisted Wireless Networks Engineering Mobile Edge Computing assisted IoT Network Characterization of Localization Algorithms over 5G wireless Nanofabrication Technology networks Photonic Integrated Circuits Optical Communications Dr Alex Man Hon WONG Microwave and Millimeter-Wave Photonics 王文瀚助理教授 Nonlinear Optics Assistant Professor of Department of Electrical Engineering Dr Chaoqiang JIANG 江朝强 助理教授 Metasurfaces Assistant Professor of Department of Electrical Metamaterials Engineering Applied Electromagnetics Antennas Electric Vehicle Technologies, Microwave and RF Systems Power Electronics, Super-Resolution Imaging Wireless Power Transfer, Superoscillation Power Converters 170

OTHER INSTITUTIONS Electromagnetics Computational Electromagnetics Dr Lijun JIANG EMC/EMI 姜立军副教授 IC Signal and Power Integrity Associate Professor of Department of Electrical and Electronic Engineering Multiphysics Characterization for The University of Hong Kong Metamaterials and Nano Devices Metamaterial Inspired Antenna Technology Material Engineering Professor Jensen Tsan Hang LI Electromagnetic and Acoustic Metamaterials 李赞恒教授 Photonic Crystals Professor of Department of Physics Transformation Optics The Hong Kong University of Science and Technology Professor Shi-Wei QU Reflective Antenna Array 屈世伟教授 New Cavity-Backed Antenna Professor of School of Electronic Engineering Ka-band Circulary Polarized Antenna University of Electronic Science and Technology of China 60GHz Wireless Communication Cavity-Backed Antenna Professor Kin-Fai (Kenneth) Tong 汤建辉教授 Fluid Antennas Professor of Antennas and Applied Electromagnetics Surface Wave Communication in University College London Millimetre-wave bands Novel Antenna Realisation Techniques Long range IoT network for Environment Monitoring 8

HONORS RECEIVED BY LABORATORY MEMBERS 实验室成员所获荣誉 Year Award Awardee(s) 2020 Dr Cheng WANG 2020 Croucher Innovation Award Prof Johnny Chung Yin HO 2020 Nano Research Top Papers Award Prof Johnny Chung Yin HO 2020 Prof Johnny Chung Yin HO 2019 Qingdao Science and Technology Award Prof Kwai Man LUK 2019 Hong Kong RGC Research Fellowship Prof Chi Hau CHAN 2019 2019 Prize for Scientific and Technological Progress by the Ho Leung Ho Lee Foundation Prof Chi Hau CHAN 2019 Dr Cheng WANG 2018 Distinguished Alumni Award 2019 by Department of Electrical and Computer Prof Johnny Chung Yin HO 2018 Engineering (ECE), University of Illinois at Urbana-Champaign Prof Johnny Chung Yin HO 2017 2019 IEEE AP-S Harrington-Mittra Computational Electromagnetics Award Prof Kwai Man LUK 2017 Dr Hang WONG NSFC Excellent Young Scientist Fund (HK & Macau) 2017 Dr Alex Man Hon WONG 2017 World Cultural Council (WCC) Special Recognition Award Prof Johnny Chung Yin HO 2016 Municipal Science and Technology Project Award, Shenzhen Science and Technology Prof Kwok Wa LEUNG Innovation Commission 2016 Prof Kwok Wa LEUNG 2017 IEEE AP-S John Kraus Antenna Award 2016 Dr Hang WONG, Best Paper Award at Les Journées Nationales Microondes - JNM2017 (National Microwaves Prof K W Leung 2015 Conference 2017) Prof Johnny Chung Yin HO 2015 Dr Alex Man Hon WONG 2014 URSI Young Scientist Award Dr Hang WONG 2014 Dr Hang WONG, Municipal Science and Technology Project Award, Shenzhen Science and Technology Dr Alex Man Hon WONG Innovation Commission First Class Award in the Natural Science category at the 2016 Higher Education Outstanding Scientific Research Output Awards (Science and Technology) from the Ministry of Education of the People’s Republic of China First Class Award (Natural Science) in the 2016 Higher Education Outstanding Scientific Research Output Awards (Science and Technology) of the Ministry of Education, China. National Science and Technology Major Project funded by the Ministry of Industry and Information Technology of the People’s Republic of China. The Shandong Province Science and Technology Prize - Second Class Award Raj Mittra Travel Grant Excellent Product Awards at 16th China Hi-Tech Fair TICRA Travel Grant 190

SELECTED RESEARCH CORAECRTEIVSEITAIERCSH FACILITIES 核心重研点究设研备究活动 While our research activities continue to focus on the millimeter-wave components and systems for 5G wireless communications, we also emphasize more on THz research, targeting the future 6G and beyond. As THz has important applications in imaging and spectroscopy, we also work on THz imaging and study the biological effects of millimeter-wave and THz irradiations on cell, tissue and system levels. Repre- sentative research outputs are going to present below to demonstrate the wide spectrum of our research. 我们的研究活动不但会继续集中在5G无线通信的毫米波组件和系统，我们也更加着重太赫兹的研究，目标是未来的 6G和更远的发展。 由于太赫兹的应用在成像和光谱方面非常重要，我们也致力研究太赫兹成像及毫米波和太赫兹在 细胞、组织和系统层面的生物效应。 以下将会介绍了代表性的研究成果，以展示我们研究范围的广泛性。 10

138 mm H DC 138 mm connector b aL 38.5 mm z xy Fig. (1a) Geometric configuration. Fig. (1b) Prototype of the low-profile transmitarray WIDEBAND LOW-PROFILE RECONFIURABLE TRANSMITARRAY 宽带低剖面可重构的发射阵列 Magneto-electric (ME) dipole is a major invention of our antenna team which set the trend of wideband antenna research worldwide since 2006. A wideband low-profile reconfigurable transmitarray (RTA) utiliz- ing ME dipole is depicted in Fig. (1a). A novel receive-transmit structure is designed as the element of the RTA by combining two ME dipoles. Using a special center-fed scheme, two PIN diodes can be integrated symmetrically into each element, result in a wideband 1-bit reconfigurable antenna element for transmitar- ra y. To r educ e t h e d i s ta n c e b e tw e e n th e fe ed source and the RTA , a w i deband refl ecti ve pol ari zat ion- con- version surface (RPCS) is designed and placed below the RTA. A low-profile structure is achieved through multi-reflections between the RTA and the RPCS. A prototype with 12×12 elements and a height-to-diame- ter-ratio (H/D) of 0.28 is shown in Fig. (1b). Excellent 2D beam scanning capability with wide scan angle of ±40° over a wide bandwidth of 32% from 10.5 to 14.5 GHz is achieved as shown in Fig. (1c). 磁电（ME）偶极子是我们天线团队的一项重要发明，自2006年以来一直引领着世界宽带天线研究的潮流。图 (1a)描 述了一个利用ME偶极子的宽带低调可重构发射阵（RTA）。 利用结合两个ME偶极子的方法，设计了一个崭新的接收- 发射结构作为RTA的元素。 透过使用一个独特的中心馈电方案，将两个PIN二极管对称地集成到每个组件中，从而形 成一个用于发射阵列的1-bit宽带可重构的天线组件。 为了减少馈电源和RTA之间的距离，发射阵用了一个宽带反射 式偏振转换面（RPCS）的设计并置于RTA的下方。 通过RTA和RPCS之间的多重反射，实现了一个薄型结构。 图 (1b))显示了一个具有12×12个元素、高度/直径比（H/D）为0.28的样品。 如图 (1c)所示，在10.5至14.5GHz的 32%的宽频带上实现了卓越的二维波束扫描能力，扫描角度为±40°。 0 0 12.5 GHz, E-plane 12.5 GHz, H-plane -5 -5 -10 -15 -20 -25 -30-90 -60 -30 0 30 60 90 Theta (deg) Normalized gain (dBi) -10 Normalized gain (dBi) -15 -20 -25 -30-90 -60 -30 0 30 60 90 Theta (deg) Fig. (1c) Measured radiation patterns at the center frequency of 12.5 GHz. 101

Fig.(2a) Glass DRAs of different shapes. Fig.(2b) DRA covering a light source. DIELECTRIC RESONATOR ANTENNAS 介质谐振器天线 We play a world leading role in dielectric resonator antenna (DRA) designs. Glass DRA (Fig. (2a)), invent- ed in 2009, is another key invention of the laboratory. It can be used as the cover of a light source as shown in Fig. (2b). Also, it can simultaneously serve as a mirror (Fig. (2c)) after being coated with a dielectric reflective film. Recently, the glass DRA has been utilized in WiFi router (Fig. (2d)) operating at 2.4-GHz band and full 5-GHz band (both 5.2-GHz and 5.8-GHz bands included). It has 6 effective antennas (two for each band), five by the glass DRA and the remaining one by the feed circuit. 本实室在电介质谐振器天线（DRA）设计方面发挥着世界领先的作用。2009年发明的玻璃DRA (图(2a))亦是本实验室 的另一项重要发明。如图(2b)所示，它们可以作为光源的覆盖物。 当玻璃DRA被涂上一层电介质反射膜，可用作一面 镜子(图(2c))。最近，玻璃DRA更用于WiFi路由器(图(2d))，应用于2.4GHz频段和5GHz全频段（包括5.2GHz和 5.8GHz频段）。我们的天线系统总共有6个有效天线（每个频段都有两个），其中5个由DRA提供，余下由1个由馈电电 路提供。 Fig. (2c) DRA with reflective film. Fig. (2d) DRAs in WiFi router. 12

PASSIVE AND ACTIVE DISCRETE METASURFACES FOR IMAGING AND COMMUNICATION 用于成像和通信的无源和有源离散超表面 The metasurface has emerged to become a ubiquitous tool for shaping electromagnetic waves. Metasur- face can modify electromagnetic waves with high flexibility and efficiency. Their flat and conformal form factor, ease of use and broad functionality attracts much interest. They see increasing applications in communication, sensing and imaging. Recent research efforts from our group aim to deepen our understanding on metasurfaces, develop novel metasurfaces of new functionalities, and demonstrate new metasurface-enabled antenna systems and microscopes. Some example projects include efficient and wideband wave redirection metasurfaces, transparent scattering reduction metasurfaces, and the active Huygens’ box. In addition, we also investi- gate the theory of superoscillation, where EM waves interfere to give sub-diffraction resolution in far-field imaging systems. 超结构表面（又称超表面）已发展成为一种多功能调改电磁波的工具。超表面可以灵活和高效地修改电磁波。 它们扁平的外形、易用性和广泛的功能引起了学界和业界的兴趣，也加快了研发速度。他们在通信、传感和成 像方面的应用也将越发曾多。 本研究组近期的研究工作旨在加深我们对超表面的基础性理解，开发具有新功能的超表面，并研发创新的超表 面天线系统和显微镜。科研项目包括高效和宽带的电磁波重定向超表面、减少散射的透明超表面和有源“惠更 斯盒”天线系统。此外，我们还研究了超振荡理论，并把成果应用在光学显微镜里，以达到远场的超分辨成像 效果。 Fig. (3) Examples of discrete Huygens’ metasurfaces. 103

WIDE IMPEDANCE- AND GAIN-BANDWIDTH Fig.2a THZ ON-CHIP ANTENNA 宽阻抗和增益带宽的太赫兹片上天线 We have designed a wide impedance- and gain-bandwidth THz on-chip antenna (OCA) with chip-integrated dielectric resonator (CIDR) backed by a ground plane, which is shown in Fig. (4a), together with the micro- graph of a fabricated OCA using TSMC 65nm CMOS technology. The antenna employs the inherent silicon substrate as a rectangular DR, i.e. CIDR. This CIDR can be seen as a standard dielectric resonator anten- na (DRA) or a magnetic-wall cavity with in-phase reflected waves from the ground. A versatile comb-shaped dipole antenna is designed above the silicon CIDR, functioning as a feeder for the DRA and an independent radiator. Multiple higher-order DR modes and the cavity mode are simultaneously excited, and contribute to the wide impedance bandwidth. 本实验室设计了一种宽阻抗和增益带宽的太赫兹片上天线（OCA），配备安装在平板上的芯片集成介电谐振器（ CIDR），如图(4a)所示，同时还显示了TSMC 65nm CMOS技术制造的OCA的显微照片。该天线采用了固有的硅 衬底作为矩形DR，即CIDR。 这个CIDR可被视为一个标准的介质谐振器天线（DRA）或一个具有地面同相反射波 的磁壁腔。 在硅CIDR上面设计了一个多功能的梳状偶极天线，既可作为DRA的馈线，亦可作为一个独立的辐射 体。 多个高阶DR模式和空腔模式同时被激发，有助于宽阻抗带宽。 Wide impedance- and gain-bandwidth THz on-chip antenna with chip-integrated dielectric resonator. Fig. (4a) On-chip antenna with a combed dipole as a feeder. / Fig. (4b) Comparison of the simulated and measured reflection coefficients. / Fig. (4c) Comparison of the simulated and realized gain. / Fig. (4d) Comparison of the simulated and measured H-plane radiation patterns at various frequencies. 14

THZ CODING METASURFACES 太赫兹编码超表面 At THz frequencies, tunable devices are not readily available. Instead, we make use of functional materi- al s s uc h as V O 2 ( v a n a d i u m d i o x i d e ) o r Ge Te (Germani um tel l uri de) w hose states can be al tered th r ough a stimulus. We develop high-frequency electronics in THz-wave radiation, detection, propagation, sensing and communications. We integrate functional materials with coding metasurfaces for beam manipulations at THz frequencies, which is actively controlled by optical activation using low-power laser sources to switch the coding pattern formation on the metasurfaces. As demonstrated in Fig. (5a), the meta atom can be fabricated on a single-layer high-frequency substrate which produces stable frequency and radiation responses over a wide THz frequency spectrum. The developed coding metasurfaces enable wideband 在太赫兹频率上，可调谐的设备并不普遍。 相反，我们利用功能材料，如VO2（二氧化钒）或GeTe（碲化锗）能够接受 刺激而改变状态的功能。 我们开发了太赫兹波辐射、检测、传播、传感和通信方面的高频电子产品。 我们将功能材料与 超表面编码整合，利用光学激活来控制太赫兹频率下的光束操作，透过使用低功率激光源来调节超表面上的编码模式。 如图(5a)所示，元原子可以在单层高频基质上加工，能在宽太赫兹频谱上产生稳定的频率和辐射响应。 所开发的超表面 编码能用于275至315GHz的宽带波束形成、滴定和转向。 这项研究工作的成果可以应用于未来的6G和更多范畴。 Focusing Tilting at 40 deg Tilting at 30 deg Splitting Pattern 1 Pattern 2 Coding Metasurface 30 30 20 20 10 10 0 0 -10-60 -40 -20 0 20 40 60 -10-60 -40 -20 0 20 40 60 Degree Degree Gain (dBi) Gain (dBi) Fig. (5a) THz coding metasurface with beam manipulation. 150

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TWO-DIMENSIONAL (2D) BEAM-SCANNING THZ BESSEL LAUNCHER 二维（2D）波束扫描太赫兹贝塞尔发射器 Bessel beams have an appealing property that they are non-diffractive, i.e., the radiation wave maintains confined. They have applications in confined-beam THz spectroscopy, non-ionizing detection and high-res- olution imaging. Through aperture phase modulation, we have demonstrated a 2D beam-scanning THz Bessel launcher based on in-plane rotation of two identical 3D printed lenses. The basic pixel element of the lens is composed of hexagonal cylinder of varying height and fixed hexagonal pyramid. By varying the height of hexagonal cylinder to control the transmission phase and the hexagonal pyramid serves as an antireflection structure. The two identical 3D printed lenses have a diameter of 15 mm corresponding to 15 wavelengths at 300 GHz with 789 elements of various height to satisfy the prescribed aperture phase distribution. Beam scanning (measured power densities) in the H-plane (yz-plane) and E-plane (xz-plane) are demonstrated, respectively, for different combinations of the orientations of the top (right) and bottom (left) lenses. 贝塞尔光束非衍射性的特性非常有趣，其辐射波能保持封闭。它们可应用于约束太赫兹光谱学、非电离探测和 高分辨率成像。 透过孔径相位调制，本实验室利用两个相同的3D打印透镜平面向内旋转，展示了一个二维波 束扫描太赫兹贝塞尔发射器。 透镜的基本像素元素是由不同高度的六边形圆柱体和固定的六边形金字塔组成 。 透过调节六边形圆柱体的高度来控制传输相位，而六边形金字塔则是作为一种抗反射结构。 当中两个相 同的3D打印透镜的直径为15毫米，相对应300GHz的15个波长，有789个不同高度的元素，以满足规定的孔径 相位分布。通过在顶部（右）和底部（左）透镜的不同定向组合，图**显示了在H面（yz面）和E面（xz面） 的光束扫描效果（测量功率密度）。 辐射场的方法而成，模拟结果（中）是用全波电磁模拟器而成。 它们都与测量结果（右）一致。 170

Two-dimensional scanning Bessel beam launcher Fig. (6a) 3D printed lenses. 300 GHz Fig. (6b) Assembled launcher. 280 GHz 320 GHz Fig. (6c) Measured magnitude of the field in yz-plane. Fig. (6d) Beam scanning in yz-plane. Fig. (6e) Beam scanning in xz-plane. 18

HIGH-GAIN LOW-PROFILE SI-IMPRINTED THZ GAUSSIAN BEAM ANTENNA 高增益、低剖面的Si-Imprinted THz高斯光束天线 Conventional high-gain THz horn and lens antennas are bulky in structure. We have demonstrated for the first time a low-profile, high-gain and high-efficiency THz antenna consisting of a leaky spherical open resonator for generating a Gaussian beam type radiation and a magneto-electric dipole feed for achieving symmetrical radiation patterns. Imprint technology was developed to construct the spherical cavity in PDMS and SU-8 2025 polymers while the dry etching process for providing high aspect ratio microstruc- tures in Si was employed to realize the magneto-electric dipole feed. These microfabrication technologies are compatible with Si-based integrated circuit manufacturing. Due to high precision in fabrication and smooth morphology in structure, the THz Gaussian beam antenna was realized with 20.3 dBi gain at 1.04 THz, 50 GHz bandwidth and much reduced profile in comparison with horns and lens antennas while exhib- iting very low side lobes. 传统的高增益太赫兹喇叭和透镜天线结构笨重。我们首次展示了一种低剖面、高增益和高效率的太赫兹天线， 该天线由用于产生高斯波束型辐射的泄漏球形开放谐振器和用于实现对称辐射模式的磁电偶极馈电组成。开发 了压印技术以在 PDMS 和 SU-8 2025 聚合物中构建球形腔，同时采用干法蚀刻工艺在 Si 中提供高纵横比微 结构以实现磁电偶极子馈电。这些微制造技术与基于硅的集成电路制造兼容。由于制造精度高和结构光滑，THz 高斯波束天线在 1.04 THz、50 GHz 带宽和 50 GHz 带宽下实现了 20.3 dBi 的增益，与喇叭和透镜天线相 比，外形大大缩小，同时具有非常低的旁瓣。 Fig. (7ai) Schematic of THz Fig. (7bi) Side view of whole structure and Fig. (7e) Simulated and measured gain. antenna. the feed. High-gain low-profile THz Gaussian beam antenna. 190

SILICON-BASED FOLDED REFLECTARRAY OPERATING AT 1 THZ 1 THz 的硅基折叠反射阵列 When the operating frequency of the antennas goes up to 1 THz, we need to make use of micro-fabrication technology to realize the designed antennas. Fig. ** shows a high-gain silicon-based folded reflectarray antenna. It consists of an open-ended waveguide, bottom main reflect array and an upper polarizer as shown in Fig. (8a). The anisotropic dielectric resonator antenna (DRA), shown in Fig. (8b), is employed as the building block of the main reflectarray to realize simultaneous phase compensation and polarization conversion. The reflectarray was fabricated using photolithography and deep reactive ion etching of high-resistive Si wafers. Fig. (8c) shows the micrograph of the fabricated main reflectarray. Fig. (8d) shows the simulated and measured H-plane far-field radiation patterns at 1.02 THz. Reasonable agree- ment between the simulated and measured results can be observed. The measured and simulated 3-dB beamwidths are 2.2o and 2.1o, respectively. The measured and simulated side lobe levels (SLLs) are -13.6 dB and -16.5 dB, respectively. 当天线的工作频率上升到1THz时，我们需要利用微加工技术来实现设计的天线。 图**显示了一个高增益的硅 基折叠反射阵天线。 如图(8a)所示，它由一个开口波导、底部主反射阵和一个上部偏振器组成。各向异性的 介质谐振器天线（DRA），如图(8b)所示，被用作主反射阵的构建模块，以实现同步相位补偿和偏振转换。 反射阵是利用光刻技术和高电阻硅片的深反应离子蚀刻技术装配。 图(8c)显示了制作的主反射阵的显微照片 。 图(8d)显示了在1.02THz下模拟和测量的H面远场辐射模式。从中可观察到模拟和测量结果之间有合理的 一致性。测量和模拟的3-dB波束宽度分别为2.2o和2.1o。测量和模拟的侧叶水平（SLLs）分别为-13.6 dB 和-16.5 dB。 Fig. (8a-d). High-gain folded reflectarray antenna operating at 1 THz. 20

TWO-DIMENSIONAL SCALABLE THZ RADIATOR ARRAYS 二维可扩展的太赫兹辐射器阵列 For future 6G communications and imaging, we need some cost-effective and compact THz sources. Novel scalable architecture of coherent harmonic oscillator arrays for high-power radiation have been developed and implemented with TSMC 65-nm CMOS technology. The first 4×4 radiator array chip operates with optimized fundamental oscillation at 230 GHz and maximized second harmonic power extraction at 460 GHz. Each array element is a slot of antenna with an oscillator. The second 4×4 radiator array chip has two oscillators with two slots of antenna in each unit cell and radiates at the third harmonic. Both chips a re i nc or por at ed w i th a n e l l i p ti c a l Te fl o n l e ns achi evi ng peak effecti ve i sotropi c radi ated pow er ( EI RP) of 29.1 dBm at 458.3 GHz and 27.8 dBm at 699 GHz. For the latter, the peak output power is 2.1 dBm and it operates from 679.4 to 716.1 GHz with a 5.26% tuning range. The core chip size is 0.61 mm2. 对于未来的6G通信和成像，我们需要一些成本效益和紧凑的太赫兹源。 能用于高功率辐射的相干谐波振荡器 阵列的新型可扩展结构已被开发，并通过台积电65纳米CMOS技术实现。 第一个4×4的辐射器阵列芯片在 230GHz时具有优化的基本振荡，在460GHz时具有最大化的二次谐波功率提取。 每个阵列元素是一个带有振 荡器的槽形天线。 第二个4×4辐射器阵列芯片有两个振荡器，每个单元中有两个槽形天线，并在三次谐波下 辐射。 这两个芯片都集成了一个椭圆特氟隆透镜，在458.3GHz时达到峰值有效各向同性辐射功率（EIRP） 29.1 dBm，在699GHz时达到27.8 dBm。对于后者，峰值输出功率有-2.1 dBm而工作频率为679.4至 716.1GHz，调谐范围为5.26%。 核心芯片的尺寸为0.61平方毫米。 Scalable THz radiator array chips. Fig. (6a) 3D printed lenses. Fig. (9b) output power among silicon-based coherent scalable radiators. 2110

Two-dimensional scanning Bessel beam launcher Fig. (9c) Fabricated chip integrated with an elliptical Teflon lens and the chip micrograph. Fig. (9d) Measured results of the chip. For the measured radiated power, VD =1.3 V with varying VG from 0.6 to 1.3 V. 22

THZ IMAGING USING ORTHOGONAL- POLARIZATION MEASUREMENTS 利用正交偏振测量进行太赫兹成像 Mueller matrix polarimetry (MMP) is at the heart of 穆勒矩阵偏振测量法（MMP）是我们理解成像样品偏 our understanding of polarization properties of an imaged sample. We compute the complete 4 × 4 振特性的核心。 我们只用了正交偏振来计算整个 MMP from 0.1 to 1 THz only using orthogonal polarizations, ±45° linear polarizations designated 0.1到1太赫兹的4×4 MMP， ±45°线性偏振指定 as P and M as depicted in Fig. (10a) for 2D and 3D imaging of a leaf. A modified THz time domain 为P和M，图(10a)展示了叶片2D和3D成像。如图 spectrometer (THz-TDS) with self-designed linear polarizers (LPs)is utilized for measurements and (10b)所示，一个已改装的太赫兹时域光谱仪（ data acquisition as shown in Fig. (10b). The Muel- ler matrix polar decomposition (MMPD) is THz-TDS）带有自行设计的线性偏振器（LPs），用 employed to facilitate extraction of polarization characteristics of the imaged leaf. Fig. (10c) 于测量和数据采集。穆勒矩阵极化分解（MMPD）能 shows the depolarization, diattenuation and retar- dance images as well as their linear and circular 用来促进成像叶片偏振特性的提取。 图(10c)显示 components. The results show weak depolariza- tion, nearly frequency-independent diattenuation 了去极化、衰减和迟滞的图像，以及它们线性和环形 and weak retardance. The time-of-flight technique is adopted to assist in the 3D reconstruction of the 的要素。 结果显示了微弱的去极化，几乎是与频率 leaf as shown in Fig. (10d). The images at differ- ent time frames correspond to the M11 images at 无关的衰减和微弱的迟滞。 图(10d)展示了采用飞 different layers and thickness. A 3D image can be constructed and the rightmost figure of Fig. (10d) 行时间技术来协助叶片的三维重建。 不同时间段的 shows the lamina of the leaf separated from the 3D leaf sample to its left. 图像对应于不同层面的M11图像，其后加起来可构建 成一个三维图像。图(10d)的最右边的图显示了从其 左边的三维叶子样本中分离出来的叶子薄片。 Fig. (10a) Reconstruction of other polarization results based on ±45° measurements. 1203

THz imaging of a leaf. Fig. (10b) Modified time-domain spectrometer. Fig. (10c) Decomposition of Mueller matrix images integrated over frequency intervals of 0.1 THz from 0.3 to 0.9 THz. Fig. (10d) M11 images of the leaf at different time delays. 24

WAVEGUIDE AMPLIFIER 波导放大器 Waveguide amplifier is an essential active building block of integrated photonic circuits, providing reliable optical gain in certain wavelength ranges. Among various amplification schemes, Erbium (Er)-doped wave- guide amplifiers (EDWA), whose gain spectrum peaks near the telecom wavelength range, are of particular interest and have been realized in many popular integrated photonic platforms, including silicon (Si), silicon nitride (SiN), and lithium niobate (LN). LN is a promising material platform for integrated photonic devices owing to its large electro-optic coefficient (r33 = 31 pm/V), large second-order nonlinear suscepti- bility (d33 = 27 pm/V) and wide transparency range (0.4 - 5 μm). However, conventional EDWA fabricated by diffusing Er3+ ions into bulk LN feature a limited optical net gain of < 3 dB/cm due to the weak optical confinement in low-index-contrast waveguides (Δn < 0.02) and the diffusion-induced non-uniform Er3+-ion distribution. Compared to bulk material, lithium niobate on insulator (LNOI) allows waveguides with much higher index contrast (Δn > 0.7), provides a promising solution to above problems, and is an emerging pho- tonic platform with great promises for future optical communications, nonlinear optics and microwave pho- tonics. However, directly diffusing Er3+ ions into LNOI substrates could be challenging due to the high diffusion temperature required (> 1100 °C). An alternative approach is to grow an Er:LN crystal first, followed by a standard ion-slicing process to form an Er:LNOI wafer. We demonstrated an EDWA based on LNOI platform experimentally with a high on-chip optical net gain of > 10 dB/cm at a signal wavelength of 1531.6 nm. The lithography defined waveguides feature strong light confinement and relatively low propa- gation loss for both 980-nm pump light and 1530-nm signal light, leading to an efficient optical gain at rela- tively low pump powers (< 20 mW). The efficient LNOI waveguide amplifiers could become an important fundamental element in future lithium niobate photonic integrated circuits. 2150

波导放大器是集成光子电路的一大重要有源组件，在某些波长范围内提供可靠的光学增益。在各种放大方案中，掺铒（ Er）的波导放大器（EDWA）接近电信波长范围的增益光谱峰值令人特别感兴趣，并且已经实现在许多流行的集成光子平 台上，包括硅（Si）、氮化硅（SiN）和铌酸锂（LN）。铌酸锂是一个很有潜力的集成光子器件的材料平台，因它具备大 电光系数（r33 = 31 pm/V）、大次位非线性易感性（d33 = 27 pm/V）和广阔的透明度范围（0.4 - 5 μm）。然而， 传统的EDWA是利用Er3+离子扩散到大块LN中制造而成，其特点是有限的光学净增益<3 dB/cm，这是由于在低指数对比度 的波导（Δn < 0.02）中，光学约束会较弱，以及由扩散引起的Er3+离子分布较为不均。与大块物料相比，绝缘体上的 铌酸锂（LNOI）允许指数对比度较高的波导（Δn>0.7），不单为上述问题提供了一个有希望的解决方案，是一个新兴的 光子平台，更为未来光学通信、非线性光学和微波光子学带来希望。然而，由于需要较高的扩散温度（>1100℃），直接 将Er3+离子扩散到LNOI基材中可能会是一个挑战。另一种方法就是先培植Er:LN晶体，然后利用标准的离子切割工艺来 形成Er:LNOI芯片。我们在实验中展示了一个基于LNOI平台的EDWA，在1531.6纳米的信号波长下，片上的光学净增益高 达>10dB/cm。以光刻技术定义的波导具有很强的光约束性和对980-nm的泵浦光和1530-nm的信号光都有相对较低的传播 损耗，从而在相对较低的泵浦功率（<20 mW）下获得高效的光学增益。高效的LNOI波导放大器可以成为未来铌酸锂光子 集成电路的一个重要基本元素。 Fig. (11a) Ion-slicing process to create Er:LNOI wafer. Insets: Appearances of Er:LN wafer (top-left) and un-doped LN wafer (top-right); Er:LNOI wafer showing green fluorescence (bottom). / Fig. (11b) Cross- section schematic of the rib-like Er:LNOI waveguides. / Fig. (11c) SEM images of a waveguide-coupled Er:LNOI microring resonator. / Fig. (11d-e) Simulated electric field profiles (Ex) of TE0 modes at 980 nm and 1530 nm. 26

INTEGRATED LITHIUM NIOBATE ELECTRO-OPTIC MODULATOR OPERATING AT 300 GHZ 300GHz的集成铌酸锂电光调制器 High-performance electro-optic modulators, that convert electrical signals into optical domain at high speeds, are key components for optical fiber communications as well as microwave photonics. Traditional LiNbO3 (LN) modulators, as the most widely used platform for decades, however are typically limited to operation bandwidths of < 40 GHz, therefore they are not capable of processing high-frequency signals in future millimeter-wave systems. In our lab, we take advantage of our low-loss and high-confinement LN nanophotonic platform to develop ultra-high-performance integrated LN modulators that could operate at frequencies up to 300 GHz, covering the entire millimeter-wave range (Fig. (12a)). We leverage the expertise of our lab to build a specialized characterization setup that features precision optical fiber coupling and millimeter-wave probe access simultaneously (Fig. (12b)). Our chip-scale LN modulators are dramatically smaller, cost orders of magnitude less power, and operate at much higher bandwidths than their traditional counterparts, and are ideal candidates for future millimeter-wave receiver systems. 将电信号高速转换为光域的高性能电光调制器，是光纤通信和微波光子学的关键部件。传统的LiNbO3（LN）调制器 是几十年来最被广泛使用的平台，然而通常被限制在<40 GHz的操作带宽，因此无法处理未来毫米波系统的高频信号。 本实验室，利用了我们的低损耗和高浓缩的LN纳米光子平台，开发出超高性能的集成LN调制器，其工作频率可达至 300GHz，覆盖整个毫米波范围（图(12a)）。我们利用本实验室的专长建立了一个专门的表征装置，其特点是同时 具有精确的光纤耦合和毫米波探针接口（图(12b)）。本实验室的芯片级LN调制器比传统的同类产品体积小很多， 能源成本亦低很多，同时工作带宽也比类似的传统仪器高很多，是未来毫米波接收系统的理想选择。 Fig. (12a) Schematic illustration of Fig. (12b) Home-built characterization Fig. (12c) Optical spectrum showing integrated LN electro-optic modulators setup with both optical fiber and efficient signal modulation at 300 GHz. operating at millimeter-wave millimeter-wave probe access. frequencies. 2107

RANDOM PHOTONIC MICROWAVE SIGNAL GENERATION BY LASER DYNAMICS 基于激光器动力学的随机光子微波信号生成 We have been working on the high-speed nonlinear dynamics of semiconductor lasers. A number of waveforms have been generated by utilizing the inherent spatiotemporal dynamics in lasers with external cavities as well as injection. Photonic millimeter-wave signals at 72 GHz have been generated in exceeding the conventional bandwidths of the lasers. Square-wave modulated photonic microwave and chaotic signals have been demonstrated for fast random bit generation (RBG), while utilizing intra-cavity physical entropies to support high output rates on the order of 100 Gb/s. 我们一直致力于研究半导体激光器的高速非线性动力学。基于外腔及外部注入，我们利用激光器内在的时空动力学生 成了不同的波形。 所生成的72 GHz 光子毫米波信号超过了激光器的传统带宽。带有方波调制的光子微波与混沌信号 也被用于快速随机数生成 (RBG)。激光器腔内物理熵支持了达100 Gb/s数量级的高输出速率。 Fig. (13a) Stable-unstable switching dynamics in semiconductor lasers for random photonic microwave generation. 28

TERAHERTZ/MILLIMETER-WAVE HYBRID WIRELESS NETWORKS 太赫兹/毫米波混合无线网络 Te ra h er t z ( T Hz ) ba n d c a n s u p p o rt a m p l e s p ectrum 太赫兹（THz）频段可以支持大量频谱，并实现百 and achieve more than hundred Gbps data rate, Gbps以上的数据传输率，但其性能却因低穿透性和 but its performance is hampered by poor 有限的覆盖范围而受限。为了克服此障碍，本实验室 pene t r abilit y and l i m i te d c o v e ra g e . To o v e rcome 测试了一个由太赫兹和毫米波单元组成的混合物联网 the aforementioned obstacles, we considered a 网络，我们利用随机的几何框架来分析混合网络的 hybrid IoT network composed of THz and 性能。考虑到准确的天线模式，我们研发了全新的 millimeter-wave cells. We used stochastic 闭合形式来显示太赫兹和毫米波网络中干扰的拉普 geometric framework to analyze the performance 拉斯变换，并评估了其覆盖概率和频谱效率。由数值 of the hybrid network. We derive a novel closed 结果可见，吸收效应降低了太赫兹网络的网络性能。 form expression of Laplace transform of 我们还发现，较大的天线阵列尺寸和较大的太赫兹 interference in THz and millimeter-wave networks 基站（TBS）偏置值可改善网络性能，而较高TBS considering accurate antenna pattern and 密度和大量的TBS偏置最终会降低网络性能。 evaluated the coverage probability and spectral efficiency. Through numerical results, we observed that the absorption effect degrades the network performance of THz networks. It is also observed that the larger antenna array size and larger bias value of THz base station (TBS) can improve the network performance, whereas higher TBS density with large amount of bias to the TBS will eventually degrade the network performance. 12094

NANO-THERANOSTIC SYSTEM 纳米阻断系统 We have recently reported a nano-theranostic system, denoted as Ce6-CuS/MSN@PDA@MnO2-FA NPs, which combines photodynamic therapy (PDT), photothermal therapy (PTT), magnetic resonance (MR) imaging with hypoxia-relieving and tumor-targeting functionalities. Central of this design is using mussel-inspired polydopamine (PDA) coating to encapsulate the Chlorin e6 (Ce6) and copper sulfide nanoparticles (CuS NPs) loaded mesoporous silica nanoparticle (MSN) core. The PDA coating not only acts as a pH sensing gatekeeper to prevent premature release of Ce6 under non-acidic tumor microenvironment (TME), but also facilitates post-functionalization so that hypoxia-relieving MnO2 nano-sheets and tumor-targeting ligand folic acid-PEG-thiol (FA-PEG-SH) can be decorated on the outer part of the drug system. In vitro and in vivo measurements clearly demonstrated that all these functionalities worked synergistically as expected. The system, having a low dark cytotoxicity, can be effectively internalized by 4T1 cells and decrease the cell viability to 2% upon 660 nm/808 nm laser irradiation. Tumors in 4T1 tumor-bearing mice can be almost completely destroyed in 2 weeks via com bi ned P D T / P T T. To g e t h e r w i t h t h e t u m o r m i cr oenvi r onm ent ( TM E ) - sensi t i ve MR imaging perf ormanc e demonstrated, Ce6-CuS/MSN@PDA@MnO2-FA NPs represent a multifunctional prototype which holds great potential to be developed I nto clinical theranostics. 本实验室最近发表了一个结合了光动力疗法（PDT）、光热疗法（PTT）、磁共振（MR）成像与缺氧缓解和肿瘤靶向 功能，名为Ce6-CuS/MSN@PDA@MnO2-FA NPs的纳米治疗系统。该设计的核心是利用贻贝启发的聚多巴胺（PDA）涂层， 将负载了Chlorin e6（Ce6）和硫化铜纳米粒子（CuS NPs）的介孔二氧化硅纳米粒子（MSN）核心封装。PDA涂层不仅 可以防止Ce6在非酸性的肿瘤微环境（TME）中过早释放，而且还容许把缓解缺氧的MnO2纳米片及肿瘤导向的 folic acid-PEG-thiol（FA-PEG-SH）装饰在药物上。体外和体内测量均清楚地显示出，这些功能全都如预期般发挥 协同作用。该系统具有低暗细胞毒性，可以被4T1细胞有效地内化，而且在660nm/808nm激光照射下，细胞活力可被下降 到2%。透过联合PDT/PTT，长在白老鼠身上的4T1肿瘤在2周内几乎可被完全消灭。连同具有肿瘤微环境（TME）敏感的 MR成像性能，Ce6-CuS/MSN@PDA@MnO2-FA NPs拥有极大的临床治疗潜力。 Fig. (14a) Schematic illustration of a nano-theranostic system. 223503

ARTIFICIAL VISUAL SYSTEM OF RECORD-LOW ENERGY CONSUMPTION FOR NEXT GENERATION OF ARTIFICIAL INTELLIGENCE (AI) 超低耗能的人工视觉系统促进新一代人工智能发展 Our team has built an ultralow-power consumption artificial visual system on flexible plastics to mimic human brain, which has successfully performed data-intensive cognitive tasks (Fig. **). Our experiment results could provide a promising device system for the next generation of artificial intelligence (AI) applications, published in Science Advances. Artificial synapse is an artificial version of synapse - the gap across which the two neurons passing through electrical signals to communicate with each other in brain. It is a device that mimics the brain's efficient neural signal transmission and memory formation process. To e nhanc e t he e n e rg y e ffi c i e n c y o f th e arti fi ci al synapses, our research team has i ntr oduced quasi-two-dimensional electron gases (quasi-2DEGs) into artificial neuromorphic systems as a pioneer. By utilizing oxide superlattice nanowires - a kind of semiconductor with intriguing electrical properties – developed by us, we have designed the quasi-2DEG photonic synaptic devices which have achieved a record-low energy consumption down to sub-femtojoule (0.7fJ) per synaptic event. It means a decrease of 93% energy consumption when compared with synapses in human brain, and the energy consumption rivals the available synapse-inspired electronics. More important, the artificial visual system, which is based on our photonic synapses, could simultaneously perform light detection, brain-like processing and memory functions in an ultralow-power manner, providing a promising strategy to build artificial neuromorphic systems for applications in bionic devices, electronic eyes, and multifunctional robotics in future. 3110

本实验室团队在可弯曲的塑料上建立了一个超低能耗的人工视觉系统以模仿人脑，已成功地执行了具密集数据的认知任务 （图**）。我们的实验结果可为下一代人工智能（AI）应用提供具前瞻性的设备系统，其结果亦 已发表在《Science Advances科学进展》上。人工突触是人工版本的突触，即大脑中两个神经元通过电信号 相互交流的间隙。它是一个模仿大脑高效神经信号传输和记忆形成过程的设备。为了提高人工突触的能量效率，我们的 研究团队率先将准二维电子气（quasi-2DEGs）引入人工神经形态系统。透过利用我们开发的氧化物超晶格纳米线， 一种具有趣的的电学特性的半导体，我们设计了准2DEG光子突触装置，实现了每次突触传输的能量消耗降低至亚微焦耳 （0.7fJ）的记录。与人脑的突触相比，人工突触是的能耗降低了93%，而且其能耗可与现有与突触相关的电子产品 相媲美。更重要的是，由于我们的光子突触的人工视觉系统可以同时以超低功率的方式进行光检测、类似大脑的处理和 记忆功能，对未来人工神经形态系统，如仿生设备、电子眼或多功能机器人的应用，是一个大有可为的策略。 Fig. (15a) Artificial visual systems enabled by quasi-two-dimensional electron gases in oxide superlattice nanowires. 32

HIGH THROUGHPUT PLATFORM FOR THE INVESTIGATION OF MILLIMETER-WAVE INFLUENCE ON THE NEURAL SYSTEM OF ZEBRAFISH LARVAE 毫米波对斑马鱼幼体神经系统影响的高通量研究平台 The human body exposes to electromagnetic field (EMF) of different frequency ranges in daily life. With the increasing prolonged use of mobile devices, the safety of related EMF on the nervous system is a public concern. The World Health Organization has recommended large-scale long-term study on mobile phone users. The majority of existing studies are unable to establish a link between EMF in wireless communications and health issues. Despite decades of research, mmWave effects remained controversial due to technical challenges such as the limited sample size in experiments that involve animal models. We are developing a high-throughput platform to investigate mmWave influence on the neural system of zebrafish larvae using significantly reduced experimental preparation and analysis time. By testing different radiation levels, a reference safety level could be identified for further studies. 在日常生活中，人体会受到不同频率范围的电磁场（EMF）的影响。 随着使用移动设备时间的增加，相关电磁场对神经 系统的安全性成为公众关注的问题。 世界卫生组织建议对手机用户进行大规模的长期研究。 现有的研究大多无法将无线 通信中的 EMF 与健康问题联结。 尽管进行了数十年的研究，但由于涉及动物模型的实验中样本量有限等技术挑战，毫米 波的影响仍然存在争议。 我们正在开发一个高通量平台，务求能大幅度减少研究毫米波对斑马鱼幼虫神经系统的影响所 需的实验准备和分析时间。 透过测试不同辐射水平，来鉴定一个安全参考水平以供将来研究之用。 3130

Fig. (16b) Fig. (16c) Fig. (16d) 34

DESIGN OF LUMINESCENT TRANSITION METAL COMPLEXES AS BIOMOLECULAR PROBES 发光的过渡金属复合物设计用作生物分子探针 Many transition metal complexes have been applied as biomolecular probes and cellular reagents because of their intense emission with large Stokes shifts. Importantly, their long emission lifetimes allow time-gated and time-resolved microscopy with enhanced sensitivity. Also, a number of complexes exhibit two-photon absorption behavior and can be readily designed to absorb and emit at long wavelengths, which can offer higher resolution, lower phototoxicity, and deeper tissue penetration. In this laboratory, photofunctional complexes carrying a molecular substrate have been developed as luminescent probes for protein receptors. Complexes modified with a reactive functional group have also been designed as biological labels. Additionally, luminescent transition metal complexes have been utilized for bioimaging and intracellular sensing. 许多过渡金属配合物被用作生物分子探针和细胞试剂，因它们具有大斯托克斯位移的强发光。重要的是，它们的长发光 寿命使时间门控和时间分辨显微成像具有更强的灵敏度。此外，许多配合物也表现出双光子吸收行为，而且通过设计 可以很容易地实现长波长下的吸收和发射，从而提供更高的分辨率、更低的光毒性和更深的组织穿透。本实验室已经 开发携带分子底物的光功能配合物为蛋白质受体的发光探针，以及设计了具反应性官能团的配合物为生物标签。此外， 发光过渡金属配合物还被用于生物成像和细胞内传感。 3105

Fig. (17a) K. K.-W. Lo. Luminescent Rhenium(I) and Iridium(III) Polypyridine Complexes as Biological Probes, Imaging Reagents, and Photocytotoxic Agents. Acc. Chem. Res. 2015, 48, 2985. K. K.-W. Lo. Molecular Design of Bioorthogonal Probes and Imaging Reagents Derived from Photofunctional Transition Metal Complexes. Acc. Chem. Res. 2020, 53, 32. 36

BIOMEDICAL DEVICES AND MICROSYSTEMS WITH INTEGRATED SENSORS AND PROCESSING UNITS 具有集成传感器和处理单元的生物医学设备和微系统 With our superb micro- and nano-fabrication capabilities, we can design and fabricate biomedical devices and microsystems for early detection and treatment of diseases. One example is a microfluidic system with plasmonic biosensors for fast, high sensitivity, low cost, portable and more accurate detection of exosomes from tumor. 凭借我们卓越的微纳米制造能力，我们可以设计和制造生物医学设备和微系统，用于疾病的早期检测和治疗。 一个例子是带有等离子体生物传感器的微流体系统，用于快速、高灵敏度、低成本、便携和更准确地检测来自 肿瘤的外泌体。 Fig. (18a) 3170

BIOMIMETIC PLATFORMS TO CONTROL Fig.2a AND SEPARATE CELLS AND BIOMOLECULES 控制和分离细胞和生物分子的仿生平台 Using nanoimprint technology, we can build 3D scaffolds with nanostructures. The surface and structural morphologies allow us to control cell locomotive behaviors. These engineered platforms allow us to separate cancer cells from normal cells. 使用纳米压印技术，我们可以构建具有纳米结构的 3D 支架。 表面和结构形态使我们能够控制细胞运动行为。 这些工程平台使我们能够将癌细胞与正常细胞分开。 Fig. (19a) 38

CORE RESEARCH FACILITIES 核心研究设备 (i) Microwave, millimeter-wave and THz antenna measurement facilities (ii) Microwave, millimeter-wave and THz circuit and IC measurement facilities (iii) THz spectroscopy measurement facilities (iv) Leica Point Scanning Confocal Microscope (Stellaris 8) 3D confocal image of nasopharyngeal car- cinoma (NPC) tumor growth in 150×150 µm2 microwells. NPC43 cancer cells (red) occupied center of microwells while NP460 nasopharyngeal epithelial cells (green) 3D confocal images of NPC tumor growth in a 50×50 µm2 microwell. NPC43 cancer cells (red) formed spheroid at center of microwell and NP460 epithelial cells (green) grew along sidewalls surrounding NPC spheroid. Fluorescence images of NP460 epithelial cells on surface with different plasma treat- ments in O2, N2, and Ar. 1309

(v) Atomic Layer Deposition System (vi) 3D printing facilities PUBLICATIONS AND PATENTS 论文和专利 Publications issued by, and projects and patents awarded to laboratory members can be accessed via below links: Publications http://www.ee.cityu.edu.hk/~sklmw/publications.html Grants http://www.ee.cityu.edu.hk/~sklmw/projects.html Patents http://www.ee.cityu.edu.hk/~sklmw/patents.html 40

STUDENT ACHIEVEMENTS 学生成就 COMPETITION / CONFERENCE AWARD YEAR T he G o ld Award in AS M Tec hnology Awar d 2021 2021 Antenna and The 21st IEEE (HK) AP/MTT Postgraduate Conference Propagation 2020 Student The 2020 IEEE Asia-Pacific Conference of Antennas and Propagation Paper Award and 2020, 2015 (APCAP) Microwave Theory 2019 a n d Te c h n i q u e s 2019 The 2019 Asia-Pacific Microwave Conference (APMC) Student Paper 2019 Award 2019 IEEE International Symposium on Antennas and Propagation (AP-S) 2015 Best Student National Sandwich PhD Scholarship Paper Award First 2015 International Workshop on Electromagnetics: Applications and Prize Student Innovation Competition IEEE Antennas and Propagation Society (AP-S) the 2015 Eugene Best Student F. K no tt Memo rial Pre - Doc t or al Res ear c h Awar d Paper Prize 2015 IEEE TENCON IEEE Hong Kong Section 2014 (Postgraduate) Student Paper Contest First Prize Student European Frequency and Time Forum Paper Award National Conference on Antennas Honorable Mention International Symposium on Antenna and Propagation Award Student Best Paper Award 2015 Young Scientist 2015 Award 2014 Student Awards 2014 Best Student Paper Award 2013 Scholarship 2015, 2014, 2010, 2009, 2008, 2007, 2006 4110

COMPETITION / CONFERENCE AWARD YEAR IEEE M i cr o w a ve Th e o r y a n d Te ch n i q u e s So ci e t y ( M T T- S) Graduate Fellowship Graduate 2004 IEEE Region 10 (Asia Pacific) Student Paper Contest Fellowship (Undergraduate) 1st Prize 2004 IEEE Region 10 Student Paper Contest (Postgraduate Category) 2nd Prize 2004 1st Prize 2008, 2004 Asia-Pacific Microwave Conference 2nd Prize 2010, 2007, 2002 3rd Prize 2003 IEEE In te r n a ti o n a l C o n f e r e n ce o n I n d u st r i a l Te ch n o l o g y Best Student IEEE International Microwave Symposium Student Paper Competition Paper Award 2005 8 th C h a l l e n g e r C u p C o m p e t i t i o n So u t h C h i n a U n i ve r si t y o f Te ch n o l o g y 7th Challenger Cup Xian Jiaotong University Best Student 2006 In te r n a ti o n a l Fu l b r i g h t Sci e n ce a n d Te ch n o l o g y Aw a r d Microwave Prize Outstanding Paper Award at the Broadband World Forum Asia Best paper 2008 International Symposium on Antennas and Propagation Champion 2008 Microwave and Millimetre-wave Symposium of China Best Paper Award 2005 1st Prize 2004 3rd Prize 2003 Distinction Award 2003 2nd Prize 2003 2nd Prize 2001 3rd Prize 2001 2007 Merit Prize 2008 Bronze Priz 2008 Certificate of Best Paper Award 2008 Best Paper Award 2007 42

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Contact | 联系 Contact | 联系 State Key Laboratory of Terahertz and Millimeter Waves (City University of Hong Kong) 太赫兹及毫米波国家重点实验室（香港城市大学) Room 15-200, 15/F, Lau Ming Wai Academic Building, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong 香港特别行政区九龙达之路83号香港城市大学刘鸣炜学术楼15楼15-200室 T | 电话 (852) 3442 4895 F | 图文传真 (852) 3442 0353 E | 电邮 [email protected] W | 网站 http://www.ee.cityu.edu.hk/~sklmw/ 44