High-Efficiency Dynamic Terahertz Deflector Utilizing a Mechanically Tunable Metasurface  

作　　者：Zhenci Sun Chao Liang Chen Chen Xiayu Wang Enze Zhou Xiaomeng Bian Yuanmu Yang Rui You Xiaoguang Zhao Jiahao Zhao Zheng You 

机构地区：[1]Department of Precision Instrument,Tsinghua University,Beijing 100084,China [2]State Key Laboratory of Precision Measurement Technology and Instruments,Tsinghua University,Beijing 100084,China [3]Beijing Advanced Innovation Center for Integrated Circuits,Beijing 100084,China [4]School of Instrument Science and Opto-Electronic Engineering,Beijing Information Science and Technology University,Beijing 100016,China.

出　　处：《Research》2024年第3期585-594,共10页研究（英文）

基　　金：the National Key R&D Program of China(Grant No.2021YFB2011800);the National Nature Science Foundation of China(Grant No.U21A6003);the United Science Foundation of Ministry of Education of China(Grant No.8091B032115);the Beijing Natural Science Foundation(Grant No.422068).X.Z.acknowledges the startup funding from Tsinghua University.

摘　　要：Terahertz (THz) wave manipulation, especially the beam deflection, plays an essential role in various applications, such as next-generation communication, space exploration, and high-resolution imaging. Current THz optical components and devices are hampered by their large bulk sizes and passive responses, limiting the development of high-performance, miniaturized THz microsystems. Tunable metasurfaces offer a powerful dynamic optical platform for controlling the propagation of electromagnetic waves. In this article, we presented a mechanically tunable metasurface (MTM), which can achieve terahertz beam deflection and vary the intensity of the anomalous reflected terahertz wave by changing the air gap between the metallic resonator (MR) array with phase discontinuities and Au ground plane. The absence of lossy spacer materials substantially enhances deflection efficiency. The device was fabricated by a combination of the surface and bulk-micromachining processes. The THz beam steering capability was characterized using terahertz time domain spectroscopy. When the air gap is 50 μm, the maximum deflection coefficient reaches 0.60 at 0.61 THz with a deflection angle of ~44.5°, consistent with theoretical predictions. We further established an electrically tunable miniaturized THz device for dynamic beam steering by introducing a micro voice coil motor to control the air gap continuously. It is shown that our designed MTM demonstrates a high modulation depth of deflection coefficient (~ 62.5%) in the target steered angle at the operating frequency. Our results showcase the potential of the proposed MTM as a platform for high-efficiency THz beam manipulation.

关 键 词：TUNABLE EFFICIENCY RESONATOR 

分 类 号：O441.4[理学—电磁学]