Tunable Terahertz Transmission Properties of Double-Layered Metal Hole-Loop Arrays Using Nematic Liquid Crystal

  • Jun Yang
  • Peng Wang
  • Sheng Gao
  • Guangsheng DengEmail author
  • Hongbo Lu
  • Weien Lai
  • Zhiping Yin
  • Ying Li
  • Yaohui Hu


This article reports on the investigation, manufacture, and testing of a liquid crystal (LC)-based tunable terahertz (THz) metamaterial (MM) metal-dielectric-metal (MDM) structure, which has low insertion loss (IL) and large modulation depth (MD). The demonstrated structure consists of two parallel layers of a quartz dielectric surrounding two copper layers. The copper structures were printed on the inner surfaces of the upper and lower surfaces of the quartz substrate, to form periodic arrays of sub-wavelength circular loops. The transmission characteristics and the LC parameters are calculated and analyzed for THz electromagnetic (EM) waves in the frequency range from 220 to 330 GHz. The experimental results show that at 285.45 GHz, 294.8 GHz, 305.91 GHz, and 314.38 GHz, the IL is below 4.08 dB and an intensity MD greater than 70.56% is available for THz EM waves with normal incidence. By varying the voltage applied to the LC layer (0–4.8 V), which contains the MDM structure, the frequency corresponding to the valley is decreased to 285.45 GHz, with a frequency tunability greater than 13.5%. The theoretical calculations and experimental results are in good agreement. The MDM structure shows good prospects for THz modulators and switches, due to its excellent performance and simple planar geometry.


Liquid crystals Terahertz Metamaterial Metal-dielectric-metal Modulators 



This work is supported by the National Natural Science Foundation of China (Grant No.61871171).


  1. 1.
    M. Hangyo, "Development and future prospects of terahertz technology," Japanese Journal Of Applied Physics 54, 120101 (2015).CrossRefGoogle Scholar
  2. 2.
    M. Tonouchi, "Cutting-edge terahertz technology," Nature Photonics 1, 97–105 (2007).CrossRefGoogle Scholar
  3. 3.
    T. Hochrein, "Markets, Availability, Notice, and Technical Performance of Terahertz Systems: Historic Development, Present, and Trends," Journal Of Infrared Millimeter And Terahertz Waves 36, 235–254 (2015).CrossRefGoogle Scholar
  4. 4.
    R. H. Xiong and J. S. Li, "Double-Layer Frequency Selective Surface for Terahertz Bandpass Filter," Journal Of Infrared Millimeter And Terahertz Waves 39, 1039–1046 (2018).CrossRefGoogle Scholar
  5. 5.
    J. Yang, C. G. Cai, Z. P. Yin, T. Y. Xia, S. C. Jing, H. B. Lu, and G. S. Deng, "Reflective liquid crystal terahertz phase shifter with tuning range of over 360°," IET Microwaves Antennas & Propagation 12, 1466–1469 (2018).CrossRefGoogle Scholar
  6. 6.
    N.I. Landy, S. Sajuyigbe, J.J. Mock, D.R. Smith, and W.J. Padilla, "Perfect metamaterial absorber," Physical Review Letters 100, 207402 (2008).CrossRefGoogle Scholar
  7. 7.
    R. S. Yan, B. Sensale-Rodriguez, L. Liu, D. Jena, and H. G. Xing, "A new class of electrically tunable metamaterial terahertz modulators," Optics Express 20, 28664–28671 (2012).CrossRefGoogle Scholar
  8. 8.
    J. H. Chen, B. C. Zheng, G. H. Shao, S. J. Ge, F. Xu, and Y. Q. Lu, "An all-optical modulator based on a stereo graphene–microfiber structure," Light Science & Applications 4, (12):e360 (2015).CrossRefGoogle Scholar
  9. 9.
    D.C. Zografopoulos and R. Beccherelli, "Tunable terahertz fishnet metamaterials based on thin nematic liquid crystal layers for fast switching," Scientific Reports 5, 13137 (2015).CrossRefGoogle Scholar
  10. 10.
    W. Duan, P. Chen, B. Y. Wei, S. J. Ge, X. Liang, W. Hu, and Y. Q. Lu, "Fast-response and high-efficiency optical switch based on dual-frequency liquid crystal polarization grating," Optical Materials Express 6, 597–602 (2016).CrossRefGoogle Scholar
  11. 11.
    T. Kleine-Ostmann and T. Nagatsuma, "A Review on Terahertz Communications Research," Journal Of Infrared Millimeter And Terahertz Waves 32, 143–171 (2011).CrossRefGoogle Scholar
  12. 12.
    C.M. Watts, D. Shrekenhamer, J. Montoya, G. Lipworth, J. Hunt, T. Sleasman, S. Krishna, D.R. Smith, and W.J. Padilla, "Terahertz compressive imaging with metamaterial spatial light modulators," Nature Photonics 8, 605–609 (2014).CrossRefGoogle Scholar
  13. 13.
    P.U. Jepsen, D.G. Cooke, and M. Koch, "Terahertz spectroscopy and imaging – Modern techniques and applications," Laser & Photonics Reviews 6, 124–166 (2012).CrossRefGoogle Scholar
  14. 14.
    H.T. Chen, J.F. O'Hara, A.K. Azad, D. Shrekenhamer, W. Padilla, J.M. Zide, A. Gossard, R.D. Averitt, and A.J. Taylor, "Active Terahertz Metamaterial Devices," Nature 444, 597–600 (2006).Google Scholar
  15. 15.
    S. Bianconi, S. Wheaton, M.S. Park, I.H. Nia, and H. Mohseni, "Machine learning optimization of surface-normal optical modulators for SWIR time-of-flight 3D camera," IEEE Journal Of Selected Topics In Quantum Electronics, PP.Google Scholar
  16. 16.
    C. Han, C. Li, J. B. Wu, X. J. Zhou, J. Li, B. B. Jin, H. B. Wang, and P. H. Wu, "A study of thermal effects in superconducting terahertz modulator by low temperature scanning laser microscope," AIP Advances 8, (6):065024 (2018).CrossRefGoogle Scholar
  17. 17.
    L. Cheng, Z. M. Jin, Z. W. Ma, F. H. Su, Y. Zhao, Y. Z. Zhang, T. Y. Su, Y. Sun, X. L. Xu, and Z. Meng, "Mechanical Terahertz Modulation Based on Single-Layered Graphene," Advanced Optical Materials 6, (7):1700877 (2018).Google Scholar
  18. 18.
    T. Kleine-Ostmann, K. Pierz, G. Hein, P. Dawson, M. Marso, and M. Koch, "Spatially resolved measurements of depletion properties of large gate two-dimensional electron gas semiconductor terahertz modulators," Journal Of Applied Physics 105, (9):093707 (2009).CrossRefGoogle Scholar
  19. 19.
    R. Kersting, G. Strasser, and K. Unterrainer, "Terahertz phase modulator," Electronics Letters 36, 1156–1158 (2000).CrossRefGoogle Scholar
  20. 20.
    T. Kleineostmann, P. Dawson, K. Pierz, G. Hein, and M. Koch, "Room-temperature operation of an electrically driven terahertz modulator," Applied Physics Letters 84, 3555–3557 (2004).CrossRefGoogle Scholar
  21. 21.
    G. S. Deng, P. Chen, J. Yang, Z. P. Yin, and L. Z. Qiu, "Graphene-based tunable polarization sensitive terahertz metamaterial absorber," Optics Communications 380, 101–107 (2016).CrossRefGoogle Scholar
  22. 22.
    B. Sensalerodriguez, R. S. Yan, M.M. Kelly, T. Fang, K. Tahy, W.S. Hwang, D. Jena, L. Liu, and H.G. Xing, "Broadband graphene terahertz modulators enabled by intraband transitions," Nature Communications 3, 780 (2012).Google Scholar
  23. 23.
    P.B. Nagy, "An Introduction to Metamaterials and Waves in Composites," Materials Today 14, 1665–1666 (2011).Google Scholar
  24. 24.
    Z. P. Yin, Y. J. Lu, T. Y. Xia, W. E. Lai, J. Yang, H. B. Lu, and G. S. Deng, "Electrically tunable terahertz dual-band metamaterial absorber based on a liquid crystal," RSC Advances 8, 4197–4203 (2018).CrossRefGoogle Scholar
  25. 25.
    N. Vieweg, M.K. Shakfa, B. Scherger, M. Mikulics, and M. Koch, "THz Properties of Nematic Liquid Crystals," Journal Of Infrared Millimeter And Terahertz Waves 31, 1312–1320 (2010).CrossRefGoogle Scholar
  26. 26.
    E. Mavrona, U. Chodorow, M.E. Barnes, J. Parka, N. Palka, S. Saitzek, J.F. Blach, V. Apostolopoulos, and M. Kaczmarek, "Refractive indices and birefringence of hybrid liquid crystal - nanoparticles composite materials in the terahertz region," AIP Advances 5, (7):077143 (2015).CrossRefGoogle Scholar
  27. 27.
    L. Wang, X.W. Lin, W. Hu, G.H. Shao, P. Chen, L.J. Liang, B.B. Jin, P.H. Wu, H. Qian, and Y.N. Lu, "Broadband tunable liquid crystal terahertz waveplates driven with porous graphene electrodes," Light Science & Applications 4, e253 (2015).CrossRefGoogle Scholar
  28. 28.
    R. Kowerdziej, L. Jaroszewicz, M. Olifierczuk, and J. Parka, "Experimental study on terahertz metamaterial embedded in nematic liquid crystal," Applied Physics Letters 106, 022908–022999 (2015).CrossRefGoogle Scholar
  29. 29.
    J. Wang, H. Tian, Y. Wang, X. Y. Li, Y. J. Cao, L. Li, J. L. Liu, and Z. X. Zhou, "Liquid crystal terahertz modulator with plasmon-induced transparency metamaterial," Optics Express 26, 5769–5776 (2018).CrossRefGoogle Scholar
  30. 30.
    S. Xia, D. X. Yang, T. Li, X. Liu, and J. Wang, "Role of surface plasmon resonant modes in anomalous terahertz transmission through double-layer metal loop arrays," Optics Letters 39, 1270–1273 (2014).CrossRefGoogle Scholar
  31. 31.
    S.A. Maier, "Plasmonics: Fundamentals and Applications," Springer Berlin 52, 49–74 (2007).Google Scholar

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Authors and Affiliations

  1. 1.National Key Laboratory of Advanced Display Technology, Academy of Photoelectric TechnologyHefei University of TechnologyHefeiChina
  2. 2.Key Laboratory of Advanced Functional Materials and Devices of Anhui Province, School of Chemistry and Chemical EngineeringHefei University of TechnologyHefeiChina

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