Skip to main content

Thank you for visiting nature.com. 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.

Designer spoof surface plasmon structures collimate terahertz laser beams

Abstract

Surface plasmons have found a broad range of applications in photonic devices at visible and near-infrared wavelengths. In contrast, longer-wavelength surface electromagnetic waves, known as Sommerfeld or Zenneck waves1,2, are characterized by poor confinement to surfaces and are therefore difficult to control using conventional metallo-dielectric plasmonic structures. However, patterning the surface with subwavelength periodic features can markedly reduce the asymptotic surface plasmon frequency, leading to ‘spoof’ surface plasmons3,4 with subwavelength confinement at infrared wavelengths and beyond, which mimic surface plasmons at much shorter wavelengths. We demonstrate that by directly sculpting designer spoof surface plasmon structures that tailor the dispersion of terahertz surface plasmon polaritons on the highly doped semiconductor facets of terahertz quantum cascade lasers, the performance of the lasers can be markedly enhanced. Using a simple one-dimensional grating design, the beam divergence of the lasers was reduced from 180° to 10°, the directivity was improved by over 10 decibels and the power collection efficiency was increased by a factor of about six compared with the original unpatterned devices. We achieve these improvements without compromising high-temperature performance of the lasers.

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

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Figure 1: Terahertz plasmonic collimator design.
Figure 2: Simulations.
Figure 3: Experimental results for a device fabricated according to the design in Fig. 1.

References

  1. Zenneck, J. Über die Fortpflanzung ebener elektromagnetischer Wellen längs einer ebenen Leiterfläche und ihre Beziehung zur drahtlosen Telegraphie. Ann. Phys. 23, 846–866 (1907).

    Article  Google Scholar 

  2. Sommerfeld, A. Über die Ausbreitung der Wellen in der drahtlosen Telegraphie. Ann. Physik 28, 665–736 (1909).

    Article  Google Scholar 

  3. Pendry, J. B., Martín-Moreno, L. & García-Vidal, F. J. Mimicking surface plasmons with structured surfaces. Science 305, 847–848 (2004).

    Article  CAS  Google Scholar 

  4. García-Vidal, F. J., Martín-Moreno, L. & Pendry, J. B. Surfaces with holes in them: New plasmonic metamaterials. J. Opt. A: Pure Appl. Opt. 7, S97–S101 (2005).

    Article  Google Scholar 

  5. Engheta, N. & Ziolkowski, R. W. Metamaterials: Physics and Engineering Explorations (Wiley-IEEE Press, 2006).

    Book  Google Scholar 

  6. Cai, W. & Shalaev, V. M. Optical Metamaterials: Fundamentals and Applications (Springer, 2009).

    Google Scholar 

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

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  9. Smolyaninov, I. I., Hung, Y-J. & Davis, C. C. Imaging and focusing properties of plasmonic metamaterial devices. Phys. Rev. B 76, 205424 (2007).

    Article  Google Scholar 

  10. Beermann, J., Radko, I. P., Boltasseva, A. & Bozhevolnyi, S. I. Localized field enhancements in fractal shaped periodic metal nanostructures. Opt. Express 15, 15234–15241 (2007).

    Article  CAS  Google Scholar 

  11. Radko, I. P. et al. Plasmonic metasurfaces for waveguiding and field enhancement. Laser Photon. Rev. 3, 575–590 (2009).

    Article  Google Scholar 

  12. Navarro-Cía, M. et al. Broadband spoof plasmons and subwavelength electromagnetic energy confinement on ultrathin metafilms. Opt. Express 17, 18184–18195 (2009).

    Article  Google Scholar 

  13. Gan, Q., Fu, Z., Ding, Y. J. & Bartoli, F. J. Ultrawide-bandwidth slow-light system based on THz plasmonic graded metallic grating structures. Phys. Rev. Lett. 100, 256803 (2008).

    Article  Google Scholar 

  14. Williams, C. R. et al. Highly confined guiding of terahertz surface plasmon polaritons on structured metal surfaces. Nature Photon. 2, 175–179 (2008).

    Article  CAS  Google Scholar 

  15. Hajenius, M. et al. Surface plasmon quantum cascade lasers as terahertz local oscillators. Opt. Lett. 33, 312–314 (2008).

    Article  CAS  Google Scholar 

  16. Kim, S. M. et al. Biomedical terahertz imaging with a quantum cascade laser. Appl. Phys. Lett. 88, 153903 (2006).

    Article  Google Scholar 

  17. Lee, A. W. M. et al. Real-time terahertz imaging over a standoff distance (>25 meters). Appl. Phys. Lett. 89, 141125 (2006).

    Article  Google Scholar 

  18. Hübers, H-W. et al. High-resolution gas phase spectroscopy with a distributed feedback terahertz quantum cascade laser. Appl. Phys. Lett. 89, 061115 (2006).

    Article  Google Scholar 

  19. Belkin, M. A. et al. High-temperature operation of terahertz quantum cascade laser sources. IEEE J. Sel. Top. Quantum Electron. 15, 952–967 (2009).

    Article  CAS  Google Scholar 

  20. Williams, B. S. Terahertz quantum-cascade lasers. Nature Photon. 1, 517–525 (2007).

    Article  CAS  Google Scholar 

  21. Scalari, G. et al. THz and sub-THz quantum cascade lasers. Laser Photon. Rev. 3, 45–66 (2009).

    Article  CAS  Google Scholar 

  22. Lee, A. W. M. et al. High-power and high-temperature THz quantum-cascade lasers based on lens-coupled metal–metal waveguides. Opt. Lett. 32, 2840–2842 (2007).

    Article  CAS  Google Scholar 

  23. Amanti, M. I., Fischer, M., Walther, C., Scalari, G. & Faist, J. Horn antennas for terahertz quantum cascade lasers. Electron. Lett. 43, 573–574 (2007).

    Article  Google Scholar 

  24. Fan, J. A. et al. Surface emitting terahertz quantum cascade laser with a double-metal waveguide. Opt. Express 14, 11672–11680 (2006).

    Article  CAS  Google Scholar 

  25. Mahler, L. et al. Vertically emitting microdisk lasers. Nature Photon. 3, 46–49 (2009).

    Article  CAS  Google Scholar 

  26. Amanti, M. I., Fischer, M., Scalari, G., Beck, M. & Faist, J. Low-divergence single-mode terahertz quantum cascade laser. Nature Photon. 3, 586–590 (2009).

    Article  CAS  Google Scholar 

  27. Chassagneux, Y. et al. Electrically pumped photonic-crystal terahertz lasers controlled by boundary conditions. Nature 457, 174–178 (2009).

    Article  CAS  Google Scholar 

  28. Yu, N. et al. Plasmonics for laser beam shaping. IEEE Trans. Nanotech. 9, 11–29 (2010).

    Article  Google Scholar 

  29. Yu, N. et al. Small-divergence semiconductor lasers by plasmonic collimation. Nature Photon. 2, 564–570 (2008).

    Article  CAS  Google Scholar 

  30. Yu, N. et al. Semiconductor lasers with integrated plasmonic polarizers. Appl. Phys. Lett. 94, 151101 (2009).

    Article  Google Scholar 

  31. Yu, N. et al. Multi-beam multi-wavelength semiconductor lasers. Appl. Phys. Lett. 95, 161108 (2009).

    Article  Google Scholar 

  32. Stutzman, W. L. & Thiele, G. A. Antenna Theory and Design (John Wiley, 1981).

    Google Scholar 

  33. Wang, B., Liu, L. & He, S. Propagation loss of terahertz surface plasmon polaritons on a periodically structured Ag surface. J. Appl. Phys. 104, 103531 (2008).

    Article  Google Scholar 

  34. Gaidis, M. C. et al. A 2.5-THz receiver front end for spaceborne applications. IEEE Trans. Microw. Theory Tech. 48, 733–739 (2000).

    Article  Google Scholar 

  35. Siegel, P. H. & Dengler, R. J. The dielectric-filled parabola: A new millimetre/submillimetre wavelength receiver/transmitter front end. IEEE Trans. Antennas Propag. 39, 40–47 (1991).

    Article  Google Scholar 

  36. Belkin, M. A. et al. Int. Workshop on Optical Terahertz Science and Technology Talk TuC5, Santa Barbara (2009).

    Google Scholar 

  37. Adam, A. J. L. et al. Beam patterns of terahertz quantum cascade lasers with subwavelength cavity dimensions. Appl. Phys. Lett. 88, 151105 (2006).

    Article  Google Scholar 

  38. Orlova, E. E. et al. Antenna model for wire lasers. Phys. Rev. Lett. 96, 173904 (2006).

    Article  CAS  Google Scholar 

  39. Fan, J. A. et al. Wide-ridge metal–metal terahertz quantum cascade lasers with high-order lateral mode suppression. Appl. Phys. Lett. 92, 031106 (2008).

    Article  Google Scholar 

  40. Huggard, P. G. et al. Drude conductivity of highly doped GaAs at terahertz frequencies. J. Appl. Phys. 87, 2382–2385 (2000).

    Article  CAS  Google Scholar 

  41. Walukiewicz, W., Lagowski, L., Jastrzebski, L., Lichtensteiger, M. & Gatos, H. C. Electron mobility and free-carrier absorption in GaAs: Determination of the compensation ratio. J. Appl. Phys. 50, 899–908 (1979).

    Article  CAS  Google Scholar 

  42. Adachi, S. GaAs and Related Materials: Bulk Semiconducting and Superlattice Properties (World Scientific Publishing Company, 1994).

    Book  Google Scholar 

Download references

Acknowledgements

We gratefully acknowledge constructive and helpful discussions with R. Blanchard, C. Pflügl, L. Diehl and A. Belyanin. M.A.K. is supported by the National Science Foundation through a Graduate Research Fellowship. We would like to thank N. Antoniou for assistance in FIB milling. We acknowledge support from AFOSR under contract No. FA9550-09-0505-DOD and the EPSRC (UK). The authors acknowledge the Center for Nanoscale Systems (CNS) at Harvard University. Harvard CNS is a member of the National Nanotechnology Infrastructure Network (NNIN). The computations in this Letter were run on the Odyssey cluster supported by the Harvard Faculty of Arts and Sciences (FAS) Sciences Division Research Computing Group.

Author information

Authors and Affiliations

Authors

Contributions

N.Y. designed the devices, in collaboration with J.A.F., and, with Q.J.W., fabricated them and carried out the experiments. M.A.K. participated in the device simulation and in the data analysis. S.P.K. and L.L. grew QCL material using molecular beam epitaxy. N.Y. and F.C. wrote the paper. F.C., A.G.D. and E.H.L. supervised the project.

Corresponding authors

Correspondence to Nanfang Yu or Federico Capasso.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

Supplementary Information (PDF 909 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Yu, N., Wang, Q., Kats, M. et al. Designer spoof surface plasmon structures collimate terahertz laser beams. Nature Mater 9, 730–735 (2010). https://doi.org/10.1038/nmat2822

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nmat2822

This article is cited by

Search

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