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Terahertz metasurface functional devices as an effective method to control terahertz waves have attracted extensive attention from researchers. In order to enhance the functionality and flexibility of the metasurface and adapt to diverse application scenarios and demands, a beam-steering controllable reflective metasurface is designed by combining the Pancharatnam-Berry phase principle and the phase change material vanadium dioxide in this work. The metasurface unit consists of five layers, they being the top layer that is a metal patterned layer, the third layer that is made of vanadium dioxide and located between the dielectric layers with different thickness, the dielectric layer that is made of polytetrafluoroethylene (PTFE), and the bottom layer that serves as a metal reflective layer. The metasurface units are rotated based on the Pancharatnam-Berry phase principle to obtain four metasurface units with fixed phase differences in between, after which the metasurface units are arranged in two dimensions based on the generalized Snell reflection law to obtain the desired phase-gradient deflected reflection beam. The insulating state-metallic state transition of the vanadium dioxide layer on the metasurface can change the phase gradient of the preset metasurface, thereby realizing the on/off function of deflection. The simulation results show that when the vanadium dioxide is in the insulating state, the phase gradient of the designed metasurface appears, and the metasurface can deflect the vertically incident circularly polarized wave with specific angle anomalies in a operating band of 1.1–2.0 THz; when the vanadium dioxide is in the metallic state, for the same operating band of the same metasurface, the phase gradient of the metasurface disappears, and the metasurface mirror reflects the vertically incident circularly polarized waves, thereby realizing the function switching. This design provides new possibilities for modulating the terahertz reflected beam, which will have potential applications in terahertz wireless communication and radar systems.
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Keywords:
- terahertz /
- encoding metasurfaces /
- beam control
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图 1 超表面单元 (a)三维示意图; (b)俯视图; (c)正视图; (d)旋转结构
Figure 1. Metasurface units: (a) 3D schematic diagram; (b) top view; (c) front view; (d) rotating structure.
图 2 x极化波和y极化波垂直入射时, 超表面单元的同极化反射幅度(a)和相位(b)
Figure 2. The co-polarized reflection amplitude (a) and phase (b) of the metasurface unit when x-polarized and y-polarized waves are vertically incident.
图 3 VO2处于绝缘态, LCP波垂直入射时, 不同旋转角α对应的超表面单元的同极化反射幅度(a)和相位(b)
Figure 3. VO2 is in an insulating state, with different rotation angles when LCP waves are vertically incident α, the amplitude (a) and phase (b) of co-polarized reflection of corresponding metasurface units.
图 4 表面电流分布 (a)—(d) VO2处于绝缘态; (e)—(h) VO2处于金属态
Figure 4. Surface current distribution: (a)–(d) VO2 is in an insulating state; (e)–(h) VO2 is in a metallic state.
图 5 不同入射角度下, 线极化波激励下超表面单元的反射相位和幅度 (a), (b)VO2处于绝缘态时, 不同入射角度下的幅度变化和相位变化; (c), (d) VO2处于金属态时, 不同入射角度下的幅度变化和相位变化
Figure 5. Reflection phase and amplitude of metasurface elements under linearly polarized wave excitation at different incident angles: (a), (b) Amplitude variation and phase change of VO2 at different incident angles when it is in an insulating state; (c), (d) amplitude variation and phase change of VO2 at different incident angles when it is in a metallic state.
图 6 2-bit反射编码超表面, LCP波垂直入射 (a)超表面排布示意图; (b)超表面结构; (c) 1.1 THz处的三维远场散射图; (d) 1.1 THz处的归一化反射振幅图; (e) 2.0 THz处的三维远场散射图; (f) 2.0 THz处的归一化反射振幅图
Figure 6. 2-bit reflection encoding metasurface, LCP wave vertically incident: (a) Schematic diagram of metasurface layout; (b) metasurface structure; (c) 3D far-field scattering map at 1.1 THz; (d) normalized reflection amplitude map at 1.1 THz; (e) 3D far-field scattering map at 2.0 THz; (f) normalized reflection amplitude map at 2.0 THz.
图 7 归一化远场辐射图
Figure 7. Normalized far-field radiation pattern.
图 8 归一化远场辐射图, 1.6 THz处不同入射角对应的反射角
Figure 8. Normalized far-field radiation pattern, reflection angles corresponding to different incident angles at 1.6 THz.
图 9 反射超表面 (a)超表面相位梯度改变示意图; (b)三维远场散射图
Figure 9. Reflective metasurface: (a) Schematic diagram of phase gradient change on metasurface; (b) 3D far-field scattering map.
表 1 超表面单元的主要参数
Table 1. Main parameters of metasurface units.
Parameter D R1 R2 L1 L2 K1 K2 T1 T2 T3 H1 H2 Value/$ {\mathrm{\mu }}{\mathrm{m}} $ 110 10 19 60 51 8 8 0.2 0.3 0.2 3 26 
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[1] Zhang Q, Cherkasov A V, Arora N, Hu G, Rudykh S 2023 Extreme Mech. Lett. 59 101957
Google Scholar
[2] Zeng J W, Luk T S, Gao J, Yang X D 2017 J. Opt. 19 125103
Google Scholar
[3] Liu S, Cui T J, Xu Q, Bao D, Du L L, Wan X, Tang W X, Ouyang C M, Zhou X Y, Yuan H, Ma H F, Jiang W X, Han J G, Zhang W L, Cheng Q 2016 Light-Sci. Appl. 5 e16076
Google Scholar
[4] Zeng Y J, Feng C H, Li Q, Su X, Yu H B 2019 IEEE Photonics J. 11 4601212
[5] Wang B X, Qin X F, Duan G Y, Yang G F, Huang W Q, Huang Z M 2024 Adv. Funct. Mater. 34 2402068
Google Scholar
[6] Zhou J, Zhao X, Huang G R, Yang X, Zhang Y, Zhan X Y, Tian H Y, Xiong Y, Wang Y X, Fu W L 2021 ACS Sens. 6 1884
Google Scholar
[7] Shi M Y, Xu C, Yang Z H, Liang J, Wang L, Tan S J, Xu G Y 2018 J. Alloy. Compd. 764 314
Google Scholar
[8] Wang H, Ling F, Zhang B 2020 Opt. Express 28 36316
Google Scholar
[9] Cui T J, Qi M Q, Wan X, Zhao J, Cheng Q 2014 Light-Sci. Appl 3 e218
Google Scholar
[10] Zhang Y G, Yin K H, Liang L J, Yao H Y, Yan X, Hu X F, Huang C C, Qiu F, Zhang R, Li Y P, Wang Y R, Li Z H, Wang Z Q 2024 Curr. Appl. Phys. 58 21
Google Scholar
[11] Orlov S, Ivaskeviciute-Povilauskiene R, Mundrys K, Kizevicius P, Nacius E, Jokubauskis D, Ikamas K, Lisauskas A, Minkevicius L, Valusis G 2024 Laser Photon. Rev.
[12] Bai S S, Yang H Y 2022 Chin. J. Integr. Med. 28 366
Google Scholar
[13] Imai R, Kanda N, Higuchi T, Zheng Z, Konishi K, Kuwata-Gonokami M 2012 Opt. Express 20 21896
Google Scholar
[14] Fedotov V 2021 Nat. Photonics 15 715
Google Scholar
[15] Liang H, Zeng H, Zhao H, Wang L, Liang S, Feng Z, Yang Z, Zhang Y 2024 J. Phys. D-Appl. Phys. 57 085104
Google Scholar
[16] Zhao F, Xu J, Song Z 2022 IEEE Photonics J. 14 1
[17] Sun S, Ma H F, Gou Y, Zhang T Y, Wu L W, Cui T J 2023 Adv. Opt. Mater. 11 2202275
Google Scholar
[18] 汪静丽, 董先超, 尹亮, 杨志雄, 万洪丹, 陈鹤鸣, 钟凯 2023 物理学报 72 098101
Google Scholar
Wang J L, Dong X C, Yin L, Yang Z X, Wan H D, Chen H M, Zhong K 2023 Acta Phys. Sin. 72 098101
Google Scholar
[19] Wu L W, Ma H F, Gou Y, Wu R Y, Wang Z X, Xiao Q, Cui T J 2022 Nanophotonics 11 2977
Google Scholar
[20] Fan J, Cheng Y 2019 J. Phys. D-Appl. Phys. 53 025109
[21] Ding Z P, Su W, Ye L P, Zhou Y H, Li W L, Zou J F, Tang B, Yao H B 2024 Phys. Chem. Chem. Phys. 26 8460
Google Scholar
[22] Jiang H, Wang J Y, Zhao S L, Ye L H, Zhang H, Zhao W R 2023 Opt. Commun. 536 129380
Google Scholar
[23] Zhao S L, Jiang H, Wang J Y, Zhu W C, Zhao W R 2023 Photonics 10 893
Google Scholar
[24] Sharma M, Hendler N, Ellenbogen T 2020 Adv. Opt. Mater. 8 1901182
Google Scholar
[25] Sorathiya V, Patel S K, Katrodiya D 2019 Opt. Mater. 91 155
Google Scholar
[26] Menzel C, Rockstuhl C, Lederer F 2010 Phys. Rev. A 82 053811
Google Scholar
[27] Zhao Y, Huang Q P, Cai H L, Lin X X, Lu Y L 2018 Opt. Commun. 426 443
Google Scholar
[28] Driscoll T, Kim H T, Chae B G, Kim B J, Lee Y W, Jokerst N M, Palit S, Smith D R, Di Ventra M, Basov D N 2009 Science 325 1518
Google Scholar
[29] Zheng Q, Zhang J, Li Y, Zheng L, Sui S, Qu S 2017 International Applied Computational Electromagnetics Society Symposium (ACES) pp1–2
[30] 杨森, 王佳云, 张婷, 于新颖 2022 光学学报 42 233
Google Scholar
Yang S, Wang J Y, Zhang T, Yu X Y 2022 Acta Opt. Sin. 42 233
Google Scholar
[31] Li J S, Yao J Q 2018 IEEE Photonics J. 10 1
[32] Born M, Wolf E 2013 Phys. Today 53 77
[33] Yu N, Genevet P, Kats M A, Aieta F, Tetienne J P, Capasso F, Gaburro Z 2011 Science 334 333
Google Scholar
[34] Ai H, Kang Q, Wang W, Guo K, Guo Z 2021 Sensors 21 4784
Google Scholar
[35] Monnai Y, Lu X, Sengupta K 2023 J. Infrared Millim. Terahertz Waves 44 169
Google Scholar
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