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Engineering

Simulation, Fabrication and Characterization of THz Metamaterial Absorbers

Published: December 27th, 2012

DOI:

10.3791/50114

1School of Engineering, University of Glasgow

This protocol outlines the simulation, fabrication and characterization of THz metamaterial absorbers. Such absorbers, when coupled with an appropriate sensor, have applications in THz imaging and spectroscopy.

Metamaterials (MM), artificial materials engineered to have properties that may not be found in nature, have been widely explored since the first theoretical1 and experimental demonstration2 of their unique properties. MMs can provide a highly controllable electromagnetic response, and to date have been demonstrated in every technologically relevant spectral range including the optical3, near IR4, mid IR5 , THz6 , mm-wave7 , microwave8 and radio9 bands. Applications include perfect lenses10, sensors11, telecommunications12, invisibility cloaks13 and filters14,15. We have recently developed single band16, dual band17 and broadband18 THz metamaterial absorber devices capable of greater than 80% absorption at the resonance peak. The concept of a MM absorber is especially important at THz frequencies where it is difficult to find strong frequency selective THz absorbers19. In our MM absorber the THz radiation is absorbed in a thickness of ~ λ/20, overcoming the thickness limitation of traditional quarter wavelength absorbers. MM absorbers naturally lend themselves to THz detection applications, such as thermal sensors, and if integrated with suitable THz sources (e.g. QCLs), could lead to compact, highly sensitive, low cost, real time THz imaging systems.

This protocol describes the simulation, fabrication and characterization of single band and broadband THz MM absorbers. The device, shown in Figure 1, consists of a metal cross and a dielectric layer on top of a metal ground plane. The cross-shaped structure is an example of an electric ring resonator (ERR)20,21 and couples strongly to uniform electric fields, but negligibly to a magnetic field. By pairing the ERR with a ground plane, the magnetic component of the incident THz wave induces a current in the sections of the ERR that are parallel to the direction of the E-field. The electric and magnetic response can then be tuned ind....

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1. Simulation of a Single Band THz Metamaterial Absorber

A 3D view of the simulation set-up is shown in Figure 2.

  1. Lumerical FDTD is used to optimize the transmission, reflection and absorption characteristics of the THz metamaterial absorber. All units are given in μm.
  2. Define the THz polyimide material properties by left clicking Materials, Add (n,k) material and inputting 1.68 as the n and 0.06 as the k. Double left click on "new.......

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Figure 5(a) shows the experimentally obtained and simulated absorption spectra for a MM absorber with a 3.1 μm thick polyimide dielectric spacer. This MM structure has a repeat-period of 27 μm and dimensions K = 26 μm, L = 20 μm, M = 10 μm and N = 5 μm. Experimental measurements were also performed on samples with no ERR layer to confirm that absorption was a consequence of the MM structure and not of the dielectric. The 7.5 μm thick polyimide sample with no ERR structur.......

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This protocol describes the simulation, fabrication and characterization of THz metamaterial absorbers. It is essential such sub-wavelength structures are accurately simulated before any effort is committed to costly fabrication procedures. Lumerical FDTD simulations provide information on not only the MM absorption spectrum but also the location of the absorption, essential knowledge to aid placement of a transducer and obtain the maximum response. In addition the optimization algorithm in Lumerical can be implem.......

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This work is supported by the Engineering and Physical Sciences Research Council grant number EP/I017461/1. We also wish to acknowledge the contribution played by the technical staff of the James Watt Nanofabrication Centre.

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Name Company Catalog Number Comments
Name of Reagent/Material Company Catalogue Number Comments
Lumerical FDTD Lumerical
Silicon wafer IDB technologies Single sided polished
Plassys 450 MEB evaporator Plassys Bestek
VM651 Primer Dupont
PI2545 Dupont
Methyl Isobutyl Ketone Sigma-Aldrich
Isopropanol Sigma-Aldrich
Plasmaprep5 barrel Asher Gala Instrumente
VB6 UHR EWF electron beam writer Vistec
Tanner L-Edit Tanner Inc.
Layout Beamer GenISys Inc.
Polymethyl methacrylate (PMMA) Sigma-Aldrich 293261 Sigma-Aldrich
IFV 66v/s FTIR Bruker
Pike 30spec reflection unit Pike Technologies
Hg arc lamp Bruker
Au mirror Thor Labs PF05-03-M01
Leica INM20 Optical Microscope Leica microsystems
6 mm Mylar Beamsplitter Bruker

  1. Pendry, J. B., Holden, A. J., Robbins, D. J., Stewart, W. J. Magnetism from conductors and enhanced nonlinear phenomena. IEEE Trans. Microw. Theory. 47, 2075-2084 (1999).
  2. Pendry, J. B., Holden, A. J., Robbins, D. J., Stewart, W. J. Magnetism from conductors and enhanced nonlinear phenomena. IEEE Microw Theory. 47, 2075-2084 (1999).
  3. Smith, D. R., Padilla, W. J., Vier, D. C., Nemat-Nasser, S. C., Schultz, S. Composite medium with simultaneously negative permeability and permittivity. Phys. Rev. Lett. 84, 4184-4187 (2000).
  4. Dolling, G., Wegener, M., Linden, S. Realization of a three-functional-layer negative-index photonic metamaterial. Opt. Lett. 32, 551-553 (2007).
  5. Zhang, S., et al. Experimental demonstration of near-infrared negative-index metamaterials. Phys. Rev. Lett. 95, 137404 (2005).
  6. Linden, S., et al. Magnetic response of metamaterials at 100 terahertz. Science. 306, 1351-1353 (2004).
  7. Landy, N. I., et al. Design, theory, and measurement of a polarization-insensitive absorber for terahertz imaging. Phys. Rev. B. 79, 125104-12 (2009).
  8. Gokkavas, M., et al. Experimental demonstration of a left-handed metamaterial operating at 100 GHz. Phys. Rev. B. 73, 193103 (2006).
  9. Smith, D. R., Kroll, N. Negative refractive index in left-handed materials. Phys. Rev. Lett. 85, 2933-2936 (2000).
  10. Wiltshire, M. C. K., et al. Microstructured magnetic materials for RF flux guides in magnetic resonance imaging. Science. 291, 849-851 (2001).
  11. Pendry, J. B. Negative refraction makes a perfect lens. Phys. Rev. Lett. 85, 3966-3969 (2000).
  12. Kabashin, A. V., et al. Plasmonic nanorod metamaterials for biosensing. Nat. Mater. 8, 867-871 (2009).
  13. Dolling, G., Enkrich, C., Wegener, M., Soukoulis, C. M., Linden, S. Low-loss negative-index metamaterial at telecommunication wavelengths. Opt. Lett. 31, 1800-1802 (2006).
  14. Schurig, D., et al. Metamaterial electromagnetic cloak at microwave frequencies. Science. 314, 977-980 (2006).
  15. Chen, H. T., et al. Experimental demonstration of frequency-agile terahertz metamaterials. Nat. Photonics. 2, 295-298 (2008).
  16. Ma, Y., Khalid, A., Saha, S. C., Grant, J. P., Cumming, D. R. S. THz band pass filter on plastic substrates and its application on biological sensing. IEEE Photonics Society Winter Topicals Meeting Series. , 50-51 (2010).
  17. Grant, J., et al. Polarization insensitive terahertz metamaterial absorber. Opt. Lett. 36, 1524-1526 (2011).
  18. Ma, Y., et al. A terahertz polarization insensitive dual band metamaterial absorber. Opt. Lett. 36, 945-947 (2011).
  19. Grant, J., Ma, Y., Saha, S., Khalid, A., Cumming, D. R. S. Polarization insensitive, broadband terahertz metamaterial absorber. Opt. Lett. 36, 3476-3478 (2011).
  20. Tonouchi, M. Cutting-edge terahertz technology. Nat. Photon. 1, 97-105 (2007).
  21. D. Schurig, J. J. M., Justice, B. J., Cummer, S. A., Pendry, J. B., Starr, A. F., Smith, D. R. Microwave Cloaking Realized. Science. 314, 889 (2006).
  22. Padilla, W. J., et al. Electrically resonant terahertz metamaterials: Theoretical and experimental investigations. Phys. Rev. B. 75, 041102 (2007).
  23. Smith, D. R., Vier, D. C., Koschny, T., Soukoulis, C. M. Electromagnetic parameter retrieval from inhomogeneous metamaterials. Phys. Rev. E. 71, (2005).
  24. Landy, N. I., Sajuyigbe, S., Mock, J. J., Smith, D. R., Padilla, W. J. Perfect metamaterial absorber. Phys. Rev. Lett. 100, 207402 (2008).
  25. Hao, J. M., et al. High performance optical absorber based on a plasmonic metamaterial. Appl. Phys. Lett. 96, 251104 (2010).
  26. Chen, H. T. Interference theory of metamaterial perfect absorbers. Opt. Express. 20, 7165-7172 (2012).
  27. Lee, A. W. M., Hu, Q. Real-time, continuous-wave terahertz imaging by use of a microbolometer focal-plane array. Optics Letters. 30, 2563-2565 (2005).
  28. Thermo Nicolet Corporation. . An Introduction to Fourier Transform Infared Spectroscopy. , (2001).

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