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Parallel-Plate Waveguide Terahertz Time Domain Spectroscopy for Ultrathin Conductive Films

  • M. RazanoelinaEmail author
  • R. Kinjo
  • K. Takayama
  • I. Kawayama
  • H. Murakami
  • Daniel M. Mittleman
  • M. Tonouchi
Article

Abstract

Development of techniques for characterization of extremely thin films is an important challenge in terahertz (THz) science and applications. Spectroscopic measurements of materials on the nanometer scale or of atomic layer thickness (2D materials) require a sufficient terahertz wave–matter interaction length, which is challenging to achieve in conventional transmission geometry. Waveguide-based THz spectroscopy offers an alternative method to overcome this problem. In this paper, we investigate a new parallel-plate waveguide (PPWG) technique for measuring dielectric properties of ultrathin gold films, in which we mount the thin film sample at the center of the waveguide. We discuss a model of THz dielectric parameter extraction based on waveguide theory and analyze the response of thin films for both transverse magnetic (TM) and transverse electric (TE) waveguide modes. In contrast to other waveguide methods, our approach enables comparison of the material response with different electromagnetic field distributions without significantly changing the experimental setup. As a result, we demonstrate that TE modes have a better sensitivity to the properties of the thin film. For prototype test samples, optical parameters extracted using our method are in good agreement with literature values.

Keywords

Thin conductive film Parallel-plate waveguide Terahertz 

Notes

Acknowledgments

This work was supported by JSPS KAKENHI Grant Number 25249049.

References

  1. 1.
    Ren, L. et al. Terahertz and Infrared Spectroscopy of Gated Large-Area Graphene. Nano Lett. 12, 3711–3715 (2012).CrossRefGoogle Scholar
  2. 2.
    Ge, S. et al. Coherent longitudinal acoustic phonon approaching THz frequency in multilayer molybdenum disulphide. Sci. Rep. 4, (2014).Google Scholar
  3. 3.
    Butler, S. Z. et al. Progress, challenges, and opportunities in two-dimensional materials beyond graphene. ACS nano 7, 2898–2926 (2013).CrossRefGoogle Scholar
  4. 4.
    Gao, W. et al. High-contrast terahertz wave modulation by gated graphene enhanced by extraordinary transmission through ring apertures. Nano Lett. 14, 1242–1248 (2014).CrossRefGoogle Scholar
  5. 5.
    Sensale-Rodriguez, B. et al. Broadband graphene terahertz modulators enabled by intraband transitions. Nat. Commun. 3, 780 (2012).CrossRefGoogle Scholar
  6. 6.
    Najmaei, S. et al. Vapour phase growth and grain boundary structure of molybdenum disulphide atomic layers. Nat Mater 12, 754–759 (2013).CrossRefGoogle Scholar
  7. 7.
    H. Hirori, K. Yamashita, M. Nagai, and K. Tanaka. Attenuated total reflection spectroscopy in time domain using terahertz coherent pulses. Jpn. J. Appl. Phys. 43, L1287 (2004).CrossRefGoogle Scholar
  8. 8.
    Zhan, H. et al. The metal-insulator transition in VO2 studied using terahertz apertureless near-field microscopy. Appl. Phys. Lett. 91, 162110–162110–3 (2007).Google Scholar
  9. 9.
    Melinger, J. S., Laman, N., Harsha, S. S. & Grischkowsky, D. Line narrowing of terahertz vibrational modes for organic thin polycrystalline films within a parallel plate waveguide. Appl. Phys. Lett. 89, 251110 (2006).CrossRefGoogle Scholar
  10. 10.
    Laman, N., Harsha, S. S., Grischkowsky, D. & Melinger, J. S. High-resolution waveguide THz spectroscopy of biological molecules. Biophys. J 94, 1010–1020 (2008).CrossRefGoogle Scholar
  11. 11.
    Zhang, J. & Grischkowsky, D. Waveguide terahertz time-domain spectroscopy of nanometer water layers. Opt. Lett. 29, 1617–1619 (2004).CrossRefGoogle Scholar
  12. 12.
    Astley, V., Reichel, K. S., Jones, J., Mendis, R. & Mittleman, D. M. Terahertz multichannel microfluidic sensor based on parallel-plate waveguide resonant cavities. Appl. Phys. Lett. 100, 231108 (2012).CrossRefGoogle Scholar
  13. 13.
    Reichel, K. S., Iwaszczuk, K., Jepsen, P. U., Mendis, R. & Mittleman, D. M. In situ spectroscopic characterization of a terahertz resonant cavity. Optica, 1, 272-275 (2014).Google Scholar
  14. 14.
    Walther, M. et al. Terahertz conductivity of thin gold films at the metal-insulator percolation transition. Phys. Rev. B 76, 125408 (2007).CrossRefGoogle Scholar
  15. 15.
    Tsankov, M. A. Permittivity measurement of a thin slab centrally located in a rectangular waveguide. J. Phys. E: Sci. Instr. 8, 963 (1975).CrossRefGoogle Scholar
  16. 16.
    Butterweck, H. Mode filters for oversized rectangular waveguides. IEEE Trans. Microw. Theory Tech. 16, 274–281 (1968).CrossRefGoogle Scholar
  17. 17.
    Maloney, J. G. & Smith, G. S. The efficient modeling of thin material sheets in the finite-difference time-domain (FDTD) method. IEEE Trans. Antennas Propag. 40, 323–330 (1992).CrossRefGoogle Scholar
  18. 18.
    Dressel, M. & Grüner, G. Electrodynamics of solids: optical properties of electrons in matter. (Cambridge University Press, 2002).Google Scholar
  19. 19.
    Gallot, G., Jamison, S. P., McGowan, R. W. & Grischkowsky, D. Terahertz waveguides. J. Opt. Soc. Am. B 17, 851–863 (2000).CrossRefGoogle Scholar
  20. 20.
    Mendis, R. & Mittleman, D. M. An investigation of the lowest-order transverse-electric (TE 1) mode of the parallel-plate waveguide for THz pulse propagation. J. Opt. Soc. Am. B 26, A6–A13 (2009).CrossRefGoogle Scholar
  21. 21.
    Ramo, S., Whinnery, J. R. & Van Duzer, T. Fields and waves in communication electronics. (J. Wiley, 1965).Google Scholar
  22. 22.
    Smith, N. V. Classical generalization of the Drude formula for the optical conductivity. Phys. Rev. B 64, 155106 (2001).CrossRefGoogle Scholar
  23. 23.
    Liu, K., Xu, J., Yuan, T. & Zhang, X.-C. Terahertz radiation from InAs induced by carrier diffusion and drift. Phys. Rev. B 73, 155330 (2006).CrossRefGoogle Scholar
  24. 24.
    Gatesman, A. J., Giles, R. H. & Waldman, J. High-precision reflectometer for submillimeter wavelengths. J. Opt. Soc. Am. B 12, 212–219 (1995).CrossRefGoogle Scholar
  25. 25.
    Thoman, A., Kern, A., Helm, H. & Walther, M. Nanostructured gold films as broadband terahertz antireflection coatings. Phys. Rev. B 77, 195405 (2008).CrossRefGoogle Scholar
  26. 26.
    Liu, J., Mendis, R. & Mittleman, D. M. The transition from a TEM-like mode to a plasmonic mode in parallel-plate waveguides. Appl. Phys. Lett. 98, 231113 (2011).CrossRefGoogle Scholar
  27. 27.
    Mendis, R. Nature of subpicosecond terahertz pulse propagation in practical dielectric-filled parallel-plate waveguides. Opt. Lett. 31, 2643–2645 (2006).CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2015

Authors and Affiliations

  • M. Razanoelina
    • 1
    Email author
  • R. Kinjo
    • 1
  • K. Takayama
    • 1
  • I. Kawayama
    • 1
  • H. Murakami
    • 1
  • Daniel M. Mittleman
    • 1
    • 2
  • M. Tonouchi
    • 1
  1. 1.Institute of Laser EngineeringOsaka UniversityOsakaJapan
  2. 2.Electrical and Computer Engineering DepartmentRice UniversityHoustonUSA

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