Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Active terahertz metamaterial devices


The development of artificially structured electromagnetic materials, termed metamaterials, has led to the realization of phenomena that cannot be obtained with natural materials1. This is especially important for the technologically relevant terahertz (1 THz = 1012 Hz) frequency regime; many materials inherently do not respond to THz radiation, and the tools that are necessary to construct devices operating within this range—sources, lenses, switches, modulators and detectors—largely do not exist. Considerable efforts are underway to fill this ‘THz gap’ in view of the useful potential applications of THz radiation2,3,4,5,6,7. Moderate progress has been made in THz generation and detection8; THz quantum cascade lasers are a recent example9. However, techniques to control and manipulate THz waves are lagging behind. Here we demonstrate an active metamaterial device capable of efficient real-time control and manipulation of THz radiation. The device consists of an array of gold electric resonator elements (the metamaterial) fabricated on a semiconductor substrate. The metamaterial array and substrate together effectively form a Schottky diode, which enables modulation of THz transmission by 50 per cent, an order of magnitude improvement over existing devices10.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Experimental design of the active THz metamaterial device.
Figure 2: Simulated and experimental characterization of THz metamaterial devices.
Figure 3: Switching performance of the active THz metamaterial device as a function of gate voltage bias with the polarization of the THz electric field perpendicular to the connecting wires.
Figure 4: Switching performance of the active THz metamaterial device as a function of gate voltage bias with the polarization of the THz electric field parallel to the connecting wires.

Similar content being viewed by others


  1. Veselago, V. G. The electrodynamics of substances with simultaneously negative values of ε and μ. Sov. Phys. Usp. 10, 509–514 (1968)

    Article  ADS  Google Scholar 

  2. Oliveira, F. et al. Neural network analysis of terahertz spectra of explosives and bio-agents. Proc. SPIE 5070, 60–70 (2003)

    Article  ADS  Google Scholar 

  3. Zimdars, D. Fiber-pigtailed terahertz time domain spectroscopy instrumentation for package inspection and security imaging. Proc. SPIE 5070, 108–116 (2003)

    Article  ADS  Google Scholar 

  4. Federici, J. F. et al. THz imaging and sensing for security applications—explosives, weapons and drugs. Semicond. Sci. Technol. 20, S266–S280 (2005)

    Article  CAS  Google Scholar 

  5. Barber, J. et al. Temperature-dependent far-infrared spectra of single crystals of high explosives using terahertz time-domain spectroscopy. J. Phys. Chem. A 109, 3501–3505 (2005)

    Article  CAS  Google Scholar 

  6. Liu, H-B., Chen, Y., Bastiaans, G. J. & Zhang, X-C. Detection and identification of explosive RDX by THz diffuse reflection spectroscopy. Opt. Express 14, 415–423 (2006)

    Article  ADS  CAS  Google Scholar 

  7. Kawase, K., Ogawa, Y., Watanabe, Y. & Inoue, H. Non-destructive terahertz imaging of illicit drugs using spectral fingerprints. Opt. Express 11, 2549–2554 (2003)

    Article  ADS  CAS  Google Scholar 

  8. Ferguson, B. & Zhang, X-C. Materials for terahertz science and technology. Nature Mater. 1, 26–33 (2002)

    Article  ADS  CAS  Google Scholar 

  9. Köhler, R. et al. Terahertz semiconductor-heterostructure laser. Nature 417, 156–159 (2002)

    Article  ADS  Google Scholar 

  10. Kleine-Ostmann, T., Dawson, P., Pierz, K., Hein, G. & Koch, M. Room-temperature operation of an electrically driven terahertz modulator. Appl. Phys. Lett. 84, 3555–3557 (2004)

    Article  ADS  CAS  Google Scholar 

  11. 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)

    Article  ADS  CAS  Google Scholar 

  12. Shelby, R. A., Smith, D. R. & Schultz, S. Experimental verification of a negative index of refraction. Science 292, 77–79 (2001)

    Article  ADS  CAS  Google Scholar 

  13. Pendry, J. B., Holden, A. J., Stewart, W. J. & Youngs, I. Extremely low frequency plasmons in metallic mesostructures. Phys. Rev. Lett. 76, 4773–4776 (1996)

    Article  ADS  CAS  Google Scholar 

  14. Pendry, J. B., Holden, A. J., Robbins, D. J. & Stewart, W. J. Magnetism from conductors and enhanced nonlinear phenomena. IEEE Trans. Microwave Theory Tech. 47, 2075–2084 (1999)

    Article  ADS  Google Scholar 

  15. Pendry, J. B. Negative refraction makes a perfect lens. Phys. Rev. Lett. 85, 3966–3969 (2000)

    Article  ADS  CAS  Google Scholar 

  16. Pendry, J. B., Schurig, D. & Smith, D. R. Controlling electromagnetic fields. Science 312, 1780–1782 (2006)

    Article  ADS  MathSciNet  CAS  Google Scholar 

  17. Leonhardt, U. Optical conformal mapping. Science 312, 1777–1780 (2006)

    Article  ADS  MathSciNet  CAS  Google Scholar 

  18. Zhang, S. et al. Experimental demonstration of near-infrared negative-index metamaterials. Phys. Rev. Lett. 95, 137404 (2005)

    Article  ADS  Google Scholar 

  19. Zhou, J. et al. Saturation of the magnetic response of split-ring resonators at optical frequencies. Phys. Rev. Lett. 95, 223902 (2005)

    Article  ADS  CAS  Google Scholar 

  20. Grigorenko, A. N. et al. Nanofabricated media with negative permeability at visible frequencies. Nature 438, 335–338 (2005)

    Article  ADS  CAS  Google Scholar 

  21. Yen, T. J. et al. Terahertz magnetic response from artificial materials. Science 303, 1494–1496 (2004)

    Article  ADS  CAS  Google Scholar 

  22. Padilla, W. J., Taylor, A. J., Highstrete, C., Lee, M. & Averitt, R. D. Dynamical electric and magnetic metamaterial response at terahertz frequencies. Phys. Rev. Lett. 96, 107401 (2006)

    Article  ADS  CAS  Google Scholar 

  23. Wang, K. & Mittleman, D. M. Metal wires for terahertz wave guiding. Nature 432, 376–379 (2004)

    Article  ADS  CAS  Google Scholar 

  24. Mendis, R. & Grischkowsky, D. THz interconnect with low-loss and low-group velocity dispersion. IEEE Microwave Wireless Compon. Lett. 11, 444–446 (2001)

    Article  Google Scholar 

  25. Kersting, R., Strasser, G. & Unterrainer, K. Terahertz phase modulator. Electron. Lett. 36, 1156–1158 (2000)

    Article  ADS  Google Scholar 

  26. Schurig, D., Mock, J. J. & Smith, D. R. Electric-field-coupled resonators for negative permittivity metamaterials. Appl. Phys. Lett. 88, 041109 (2006)

    Article  ADS  Google Scholar 

  27. Ikonen, P. & Tretyakov, S. Generalized permeability function and field energy density in artificial magnetics. Preprint at 〈〉 (2006)

  28. Grischkowsky, D., Keiding, S., van Exter, M. & Fattinger Far-infrared time-domain spectroscopy with terahertz beams of dielectrics and semiconductors. J. Opt. Soc. Am. B 7, 2006–2015 (1990)

    Article  ADS  CAS  Google Scholar 

  29. O’Hara, J. F., Zide, J. M. O., Gossard, A. C., Taylor, A. J. & Averitt, R. D. Enhanced terahertz detection via ErAs:GaAs nanoisland superlattices. Appl. Phys. Lett. 88, 251119 (2006)

    Article  ADS  Google Scholar 

Download references


We acknowledge support from the Los Alamos National Laboratory LDRD programme, and from the Center for Integrated Nanotechnologies.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Hou-Tong Chen.

Ethics declarations

Competing interests

Reprints and permissions information is available at The authors declare no competing financial interests.

Supplementary information

Supplementary Figures

This file contains Supplementary Figures 1–2. (PDF 72 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Chen, HT., Padilla, W., Zide, J. et al. Active terahertz metamaterial devices. Nature 444, 597–600 (2006).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing