Bandwidth Enhancement of Planar Terahertz Metasurfaces via Overlapping of Dipolar Modes


We present enhancement of operational bandwidths of planar terahertz metasurfaces by incorporating a complex unit cell that consists of a pair of concentric ring resonators. The inner resonator is a closed ring, while the outer resonator contains a pair of split gaps introduced symmetrically into the two opposite arms. The enhancement of the bandwidth is attributed to the spectral overlapping of the resonant responses arising from both the resonators. A total of five metasurface samples (MM1 to MM5) have been designed, fabricated, and characterized using terahertz time domain spectroscopy (THz-TDS). Resonance broadening along with the blue shifting of higher order resonance mode is being observed while introducing the split gaps in the outer ring and increasing the split gap length (MM1 to MM5) successively. We have further performed detailed numerical investigations in order to explain the experimental observations which support the experimental results. Such metasurfaces can pave the way to realize versatile photonic applications including broadband modulators and band stop filters in the comparatively lesser explored yet technologically relevant terahertz region.

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  1. 1.

    Smith DR, Padilla WJ, Vier DC, Nemat-Nasser SC, Schultz S (2000) Composite medium with simultaneously negative permeability and permittivity. Phys Rev Lett 84(18):4184–4187

    CAS  PubMed  Google Scholar 

  2. 2.

    Zheludev NI (2010) The road ahead for metamaterials. Science 328(5978):582–583

    CAS  PubMed  Google Scholar 

  3. 3.

    Powell DA, Lapine M, Gorkunov MV, Shadrivov IV, Kivshar YS (2010) Metamaterial tuning by manipulation of near-field interaction. Phys Rev B 82(15):155128

    Google Scholar 

  4. 4.

    Shelby RA, Smith DR, Schultz S (2001) Experimental verification of a negative index of refraction. Science 292(5514):77–79

    CAS  PubMed  Google Scholar 

  5. 5.

    Soydan MC, Ghobadi A, Yildirim DU, Erturk VB, Ozbay E (2019) All ceramic-based metal-free ultra-broadband perfect absorber. Plasmonics 14:1–15.

    CAS  Article  Google Scholar 

  6. 6.

    Liu W, Lan C, Gao Z, Bi K, Fu X, Li B, Zhou J (2017) Enhancement of electrostatic field by a metamaterial electrostatic concentrator. J Alloys Compd 724:1064–1069

    CAS  Google Scholar 

  7. 7.

    Shin D, Urzhumov Y, Jung Y, Kang G, Baek S, Choi M, Park H, Kim K, Smith DR (2012) Broadband electromagnetic cloaking with smart metamaterials. Nat Commun 3:1213

    PubMed  Google Scholar 

  8. 8.

    Shu L, Yu Y, Yong Z, Rao Z, Ke S, Fei L, Zhang S, Wang Y (2019) Negative Coriolis effect in piezoelectric metamaterials. J Alloys Compd 801:262–266.

    CAS  Article  Google Scholar 

  9. 9.

    Landy NI, Sajuyigbe S, Mock JJ, Smith DR, Padilla WJ (2008) Perfect metamaterial absorber. Phys Rev Lett 100(20):207402

    CAS  PubMed  Google Scholar 

  10. 10.

    He Y, Wu Q, Yan S (2019) Multi-band terahertz absorber at 0.1–1 THz frequency based on ultra-thin metamaterial. Plasmonics:1–8.

  11. 11.

    Meng HY, Wang LL, Zhai X, Liu GD, Xia SX (2018) A simple design of a multi-band terahertz metamaterial absorber based on periodic square metallic layer with T-shaped gap. Plasmonics 13(1):269–274

    CAS  Google Scholar 

  12. 12.

    Dayal G, Ramakrishna SA (2012) Design of highly absorbing metamaterials for infrared frequencies. Opt Express 20(16):17503–17508

    CAS  PubMed  Google Scholar 

  13. 13.

    Pendry JB, Holden AJ, Robbins DJ, Stewart WJ (1999) Magnetism from conductors and enhanced nonlinear phenomena. IEEE Trans Microw Theory Tech 47(11):2075–2084

    Google Scholar 

  14. 14.

    Rao SJ, Kumar D, Kumar G, Chowdhury DR (2017) Modulating the near field coupling through resonator displacement in planar terahertz metamaterials. J Infrared Millim Terahertz Waves 38(1):124–134

    Google Scholar 

  15. 15.

    Chowdhury DR, Azad AK, Zhang W, Singh R (2013) Near field coupling in passive and active terahertz metamaterial devices. IEEE Trans Terahertz Sci Technol 3(6):783–790

    CAS  Google Scholar 

  16. 16.

    Chen X, Grzegorczyk TM, Wu BI, Pacheco J Jr, Kong JA (2004) Robust method to retrieve the constitutive effective parameters of metamaterials. Phys Rev E 70(1):016608

    Google Scholar 

  17. 17.

    Liu Y, Du Y, Liu W, Shen S, Tan Q, Xiong J, Zhang W (2019) Tunable plasmon-induced transparency with ultra-broadband in Dirac semimetal metamaterials. Plasmonics:1–7.

  18. 18.

    Roy Chowdhury D, Singh R, O’Hara JF, Chen HT, Taylor AJ, Azad AK (2011) Dynamically reconfigurable terahertz metamaterial through photo-doped semiconductor. Appl Phys Lett 99(23):231101

    Google Scholar 

  19. 19.

    Alu A, Silveirinha MG, Salandrino A, Engheta N (2007) Epsilon-near-zero metamaterials and electromagnetic sources: tailoring the radiation phase pattern. Phys Rev B 75(15):155410

    Google Scholar 

  20. 20.

    Tang J, Xiao Z, Xu K, Ma X, Wang Z (2016) Polarization-controlled metamaterial absorber with extremely bandwidth and wide incidence angle. Plasmonics 11(5):1393–1399

    CAS  Google Scholar 

  21. 21.

    Rubin NA, Zaidi A, Juhl M, Li RP, Mueller JB, Devlin RC, Leósson K, Capasso F (2018) Polarization state generation and measurement with a single metasurface. Opt Express 26(17):21455–21478

    CAS  PubMed  Google Scholar 

  22. 22.

    Zheludev NI, Kivshar YS (2012) From metamaterials to metadevices. Nat Mater 11(11):917–924

    CAS  PubMed  Google Scholar 

  23. 23.

    Manikandan E, Princy SS, Sreeja BS, Radha S (2019) Structure metallic surface for terahertz plasmonics. Plasmonics:1–9.

  24. 24.

    Chen L, Qu SW, Chen BJ, Bai X, Ng KB, Chan CH (2016) Terahertz metasurfaces for absorber or reflectarray applications. IEEE Trans Antennas Propag 65(1):234–241

    Google Scholar 

  25. 25.

    Zhang C, Divitt S, Fan Q, Zhu W, Agrawal A, Lu Y, Xu T, Lezec HJ (2020) Low-loss metasurface optics down to the deep ultraviolet region. Light Sci Appl 9(1):1–10

    CAS  Google Scholar 

  26. 26.

    Tonouchi M (2007) Cutting-edge terahertz technology. Nat Photonics 1(2):97–105

    CAS  Google Scholar 

  27. 27.

    Trofimov VA, Varentsova SA (2016) Detection and identification of drugs under real conditions by using noisy terahertz broadband pulse. Appl Opt 55(33):9605–9618

    CAS  PubMed  Google Scholar 

  28. 28.

    Liu HB, Chen Y, Bastiaans GJ, Zhang XC (2006) Detection and identification of explosive RDX by THz diffuse reflection spectroscopy. Opt Express 14(1):415–423

    CAS  PubMed  Google Scholar 

  29. 29.

    Karaliūnas M, Nasser KE, Urbanowicz A, Kašalynas I, Bražinskienė D, Asadauskas S, Valušis G (2018) Non-destructive inspection of food and technical oils by terahertz spectroscopy. Sci Rep 8(1):18025

    PubMed  PubMed Central  Google Scholar 

  30. 30.

    Liu X, Starr T, Starr AF, Padilla WJ (2010) Infrared spatial and frequency selective metamaterial with near-unity absorbance. Phys Rev Lett 104(20):207403

    PubMed  Google Scholar 

  31. 31.

    Wen Y, Ma W, Bailey J, Matmon G, Yu X (2015) Broadband terahertz metamaterial absorber based on asymmetric resonators with perfect absorption. IEEE Trans Terahertz Sci Technol 5(3):406–411

    Google Scholar 

  32. 32.

    George PA, Strait J, Dawlaty J, Shivaraman S, Chandrashekhar M, Rana F, Spencer MG (2008) Ultrafast optical-pump terahertz-probe spectroscopy of the carrier relaxation and recombination dynamics in epitaxial graphene. Nano Lett 8(12):4248–4251

    CAS  PubMed  Google Scholar 

  33. 33.

    Ahmadivand A, Gerislioglu B, Ahuja R, Mishra YK (2019) Terahertz plasmonics: the rise of toroidal metadevices towards immunobiosensings. Mater Today 32:108–130.

    CAS  Article  Google Scholar 

  34. 34.

    Tao H, Strikwerda AC, Fan K, Padilla WJ, Zhang X, Averitt RD (2009) Reconfigurable terahertz metamaterials. Phys Rev Lett 103(14):147401

    PubMed  Google Scholar 

  35. 35.

    Chaudhary RP, Das B, Oh SI, Kim DS (2019) Efficient control of THz transmission of PEDOT: PSS with resonant nano-metamaterials. Sci Rep 9(1):1–7

    Google Scholar 

  36. 36.

    Karmakar S, Banerjee S, Kumar D, Kamble G, Varshney RK, Roy Chowdhury D (2019) Deep-subwavelength coupling-induced Fano resonances in symmetric terahertz metamaterials. Phys Status Solidi RRL 13(10):1900310

    CAS  Google Scholar 

  37. 37.

    Banerjee S, Amith CS, Kumar D, Damarla G, Chaudhary AK, Goel S, Pal BP, Chowdhury DR (2019) Ultra-thin subwavelength film sensing through the excitation of dark modes in THz metasurfaces. Opt Commun 453:124366

    CAS  Google Scholar 

  38. 38.

    Rao SJ, Kumar D, Kumar G, Chowdhury DR (2016) Probing the near-field inductive coupling in broadside coupled terahertz metamaterials. IEEE J Sel Top Quantum Electron 23(4):1–7

    CAS  Google Scholar 

  39. 39.

    Rana G, Deshmukh P, Palkhivala S, Gupta A, Duttagupta SP, Prabhu SS, Achanta V, Agarwal GS (2018) Quadrupole-quadrupole interactions to control plasmon-induced transparency. Phys Rev Appl 9(6):064015

    CAS  Google Scholar 

  40. 40.

    Ako RT, Upadhyay A, Withayachumnankul W, Bhaskaran M, Sriram S (2019) Dielectrics for terahertz metasurfaces: material selection and fabrication techniques. Adv Opt Mater 8(3): 1900750

  41. 41.

    Xia D, Ku Z, Lee SC, Brueck SRJ (2011) Nanostructures and functional materials fabricated by interferometric lithography. Adv Mater 23(2):147–179

    CAS  PubMed  Google Scholar 

  42. 42.

    Kadic M, Milton GW, van Hecke M, Wegener M (2019) 3D metamaterials. Nat Rev Phys 1(3):198–210

    Google Scholar 

  43. 43.

    Jansen C, Al-Naib IA, Born N, Koch M (2011) Terahertz metasurfaces with high Q-factors. Appl Phys Lett 98(5):051109

    Google Scholar 

  44. 44.

    Chowdhury DR, Singh R, Reiten M, Zhou J, Taylor AJ, O’Hara JF (2011) Tailored resonator coupling for modifying the terahertz metamaterial response. Opt Express 19(11):10679–10685

    PubMed  Google Scholar 

  45. 45.

    Al-Naib IA, Jansen C, Born N, Koch M (2011) Polarization and angle independent terahertz metamaterials with high Q-factors. Appl Phys Lett 98(9):091107

    Google Scholar 

  46. 46.

    Chau YF, Yeh HH, Tsai DP (2009) Surface plasmon effects excitation from three-pair arrays of silver-shell nanocylinders. Phys Plasmas 16(2):022303

    Google Scholar 

  47. 47.

    Kumara NTRN, Chau YFC, Huang JW, Huang HJ, Lin CT, Chiang HP (2016) Plasmonic spectrum on 1D and 2D periodic arrays of rod-shape metal nanoparticle pairs with different core patterns for biosensor and solar cell applications. J Opt 18(11):115003

    Google Scholar 

  48. 48.

    Liu X, Tyler T, Starr T, Starr AF, Jokerst NM, Padilla WJ (2011) Taming the blackbody with infrared metamaterials as selective thermal emitters. Phys Rev Lett 107(4):045901

    PubMed  Google Scholar 

  49. 49.

    Zhang Y, Feng Y, Jiang T, Cao J, Zhao J, Zhu B (2018) Tunable broadband polarization rotator in terahertz frequency based on graphene metamaterial. Carbon 133:170–175

    CAS  Google Scholar 

  50. 50.

    Chowdhury DR, Singh R, Reiten M, Chen HT, Taylor AJ, O’Hara JF, Azad AK (2011) A broadband planar terahertz metamaterial with nested structure. Opt Express 19(17):15817–15823

    PubMed  Google Scholar 

  51. 51.

    Han NR, Chen ZC, Lim CS, Ng B, Hong MH (2011) Broadband multi-layer terahertz metamaterials fabrication and characterization on flexible substrates. Opt Express 19(8):6990–6998

    CAS  PubMed  Google Scholar 

  52. 52.

    Zhu J, Ma Z, Sun W, Ding F, He Q, Zhou L, Ma Y (2014) Ultra-broadband terahertz metamaterial absorber. Appl Phys Lett 105(2):021102

    Google Scholar 

  53. 53.

    Huang L, Chowdhury DR, Ramani S, Reiten MT, Luo SN, Taylor AJ, Chen HT (2012) Experimental demonstration of terahertz metamaterial absorbers with a broad and flat high absorption band. Opt Lett 37(2):154–156

    PubMed  Google Scholar 

  54. 54.

    Liu N, Guo H, Fu L, Kaiser S, Schweizer H, Giessen H (2008) Three-dimensional photonic metamaterials at optical frequencies. Nat Mater 7(1):31–37

    CAS  PubMed  Google Scholar 

  55. 55.

    Ling F, Zhong Z, Huang R, Zhang B (2018) A broadband tunable terahertz negative refractive index metamaterial. Sci Rep 8(1):9843

    PubMed  PubMed Central  Google Scholar 

  56. 56.

    Fan K, Strikwerda AC, Zhang X, Averitt RD (2013) Three-dimensional broadband tunable terahertz metamaterials. Phys Rev B 87(16):161104

    Google Scholar 

  57. 57.

    Chau YFC (2019) Plasmonic effects in the enclosed and opened metallodielectric bowtie nanostructures. Opt Commun 450:180–189

    Google Scholar 

  58. 58.

    Chou Chau YF, Lim CM, Lee C, Huang HJ, Lin CT, Kumara NTRN, Yoong VN, Chiang HP (2016) Tailoring surface plasmon resonance and dipole cavity plasmon modes of scattering cross section spectra on the single solid-gold/gold-shell nanorod. J Appl Phys 120(9):093110

    Google Scholar 

  59. 59.

    Chau YFC, Jiang JC, Chao CTC, Chiang HP, Lim CM (2016) Manipulating near field enhancement and optical spectrum in a pair-array of the cavity resonance based plasmonic nanoantennas. J Phys D Appl Phys 49(47):475102

    Google Scholar 

  60. 60.

    Chau YFC, Syu JY, Chao CTC, Chiang HP, Lim CM (2017) Design of crossing metallic metasurface arrays based on high sensitivity of gap enhancement and transmittance shift for plasmonic sensing applications. J Phys D Appl Phys 50(4):045105

    Google Scholar 

  61. 61.

    Roy Chowdhury D, Xu N, Zhang W, Singh R (2015) Resonance tuning due to coulomb interaction in strong near-field coupled metamaterials. J Appl Phys 118(2):023104

    Google Scholar 

  62. 62.

    Grischkowsky D, Keiding S, Van Exter M, Fattinger C (1990) Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors. JOSA B 7(10):2006–2015

    CAS  Google Scholar 

  63. 63.

    Wu Q, Litz M, Zhang XC (1996) Broadband detection capability of ZnTe electro-optic field detectors. Appl Phys Lett 68(21):2924–2926

    CAS  Google Scholar 

  64. 64.

    Chou Chau YF, Chen KH, Chiang HP, Lim CM, Huang HJ, Lai CH, Kumara NTRN (2019) Fabrication and characterization of a metallic–dielectric nanorod array by nanosphere lithography for plasmonic sensing application. Nanomaterials 9(12):1691

    PubMed Central  Google Scholar 

  65. 65.

    Katsarakis N, Koschny T, Kafesaki M, Economou EN, Soukoulis CM (2004) Electric coupling to the magnetic resonance of split ring resonators. Appl Phys Lett 84(15):2943–2945

    CAS  Google Scholar 

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DK acknowledges financial support received via Department of Science & Technology (DST) INSPIRE doctoral research fellowship, Ministry of Science and Technology, Government of India. Authors DRC and SB acknowledge support from Department of Science & Technology (DST), project EMR/2015/001339. We also acknowledge support from the Los Alamos National Laboratory LDRD Program and the Center for Integrated Nanotechnologies, a US Department of Energy, Office of Basic Energy Sciences Nanoscale Science Research Centre operated jointly by Los Alamos and Sandia National Laboratories.

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Correspondence to Dibakar Roy Chowdhury.

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Kumar, D., Jain, R., Shahjahan et al. Bandwidth Enhancement of Planar Terahertz Metasurfaces via Overlapping of Dipolar Modes. Plasmonics (2020).

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  • Broadband
  • Metasurface
  • Metamaterial
  • Resonance
  • Terahertz