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.

  • Article
  • Published:

Nanofocusing in a metal–insulator–metal gap plasmon waveguide with a three-dimensional linear taper

Abstract

The development of techniques for efficiently confining photons on the deep sub-wavelength spatial scale will revolutionize scientific research and engineering practices. The efficient coupling of light into extremely small nanofocusing devices has been a major challenge in on-chip nanophotonics because of the need to overcome various loss mechanisms and the on-chip nanofabrication challenges. Here, we demonstrate experimentally the achievement of highly efficient nanofocusing in an Au–SiO2–Au gap plasmon waveguide using a carefully engineered three-dimensional taper. The dimensions of the SiO2 layer, perpendicular to the direction of wave propagation, taper linearly below 100 nm. Our simulations suggest that the three-dimensional linear-tapering approach could focus 830 nm light into a 2 × 5 nm2 area with ≤3 dB loss and an intensity enhancement of 3.0 × 104. In a two-photon luminescence measurement, our device achieved an intensity enhancement of 400 within a 14 × 80 nm2 area, and a transmittance of 74%.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Figure 1: The 3D NPC.
Figure 2: Simulation of a 3D NPC with an infinite tip.
Figure 3: Simulation of a 3D NPC with a finite tip.
Figure 4: Fabricated 3D NPC and optical characterization setup.
Figure 5: Optical characterization of the 3D NPC.

Similar content being viewed by others

References

  1. Hill, M. T. et al. Lasing in metallic-coated nanocavities. Nature Photon. 1, 589–594 (2007).

    Article  ADS  Google Scholar 

  2. Noginov, M. A. et al. Demonstration of a spaser-based nanolaser. Nature 460, 1110–1112 (2009).

    Article  ADS  Google Scholar 

  3. Oulton, R. F. et al. Plasmon lasers at deep subwavelength scale. Nature 461, 629–632 (2009).

    Article  ADS  Google Scholar 

  4. Khajavikhan, M. et al. Thresholdless nanoscale coaxial lasers. Nature 482, 204–207 (2012).

    Article  ADS  Google Scholar 

  5. Tang, L. et al. Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna. Nature Photon. 2, 226–229 (2008).

    Article  Google Scholar 

  6. Neutens, P., Van Dorpe, P., De Vlaminck, I., Lagae, L. & Borghs, G. Electrical detection of confined gap plasmons in metal–insulator–metal waveguides. Nature Photon. 3, 283–286 (2009).

    Article  ADS  Google Scholar 

  7. Nikolajsen, T., Leosson, K. & Bozhevolnyi, S. I. Surface plasmon polariton modulators and switches operating at telecom wavelengths. Appl. Phys. Lett. 85, 5833–5835 (2004).

    Article  ADS  Google Scholar 

  8. Cai, W., White, J. S. & Brongersma, M. L. Compact, high-speed and power-efficient electrooptic plasmonic modulators. Nano. Lett. 9, 4403–4411 (2009).

    Article  ADS  Google Scholar 

  9. Anger, P., Bharadwaj, P. & Novotny, L. Enhancement and quenching of single-molecule fluorescence. Phys. Rev. Lett. 96, 113002 (2006).

    Article  ADS  Google Scholar 

  10. Taminiau, T. H., Stefani, F. D., Segerink, F. B. & Van Hulst, N. F. Optical antennas direct single-molecule emission. Nature Photon. 2, 234–237 (2008).

    Article  Google Scholar 

  11. Okamoto, K. et al. Surface-plasmon-enhanced light emitters based on InGaN quantum wells. Nature Mater. 3, 601–605 (2004).

    Article  ADS  Google Scholar 

  12. Yuan, Z. et al. Electrically driven single-photon source. Science 295, 102–105 (2002).

    Article  ADS  Google Scholar 

  13. Akimov, A. V. et al. Generation of single optical plasmons in metallic nanowires coupled to quantum dot. Nature 450, 402–406 (2007).

    Article  ADS  Google Scholar 

  14. Maier, S. A. A. Plasmonics: Fundamentals and Applications (Springer, 2007).

    Book  Google Scholar 

  15. Gramotnev, D. K. & Bozhevolnyi, S. I. Plasmonics beyond the diffraction limit. Nature Photon. 4, 83–91 (2010).

    Article  ADS  Google Scholar 

  16. Volkov, V. S. et al. Nanofocusing with channel plasmon polaritons. Nano Lett. 9, 1278–1282 (2009).

    Article  ADS  Google Scholar 

  17. Vernon, K. C., Gramotnev, D. K. & Pile, D. F. P. Adiabatic nanofocusing of plasmons by a sharp metal wedge on a dielectric substrate. J. Appl. Phys. 101, 104312 (2007).

    Article  ADS  Google Scholar 

  18. Verhagen, E., Kuipers, L. & Polman, A. Plasmonic nanofocusing in a dielectric wedge. Nano Lett. 10, 3665–3669 (2010).

    Article  ADS  Google Scholar 

  19. Schnell, M. et al. Nanofocusing of mid-infrared energy with tapered transmission lines. Nature Photon. 5, 283–287 (2011).

    Article  ADS  Google Scholar 

  20. Davoyan, A. R., Shadrivov, I. V., Zharov, A. A., Gramotnev, D. K. & Kivshar, Y. S. Nonlinear nanofocusing in tapered plasmonic waveguides. Phys. Rev. Lett. 105, 116804 (2010).

    Article  ADS  Google Scholar 

  21. Gramotnev, D. K., Pile, D. F. P., Vogel, M. W. & Zhang, X. Local electric field enhancement during nanofocusing of plasmons by a tapered gap. Phys. Rev. B 75, 035431 (2007).

    Article  ADS  Google Scholar 

  22. Pile, D. F. P. & Gramotnev, D. K. Adiabatic and nonadiabatic nanofocusing of plasmons by tapered gap plasmon waveguides. Appl. Phys. Lett. 89, 04111 (2006).

    Google Scholar 

  23. Choi, H., Pile, D. F. P., Nam, S., Bartal, G. & Zhang, X. Compressing surface plasmons for nano-scale optical focusing. Opt. Express 17, 7519–7524 (2009).

    Article  ADS  Google Scholar 

  24. Stockman, M. I. Nanofocusing of optical energy in tapered plasmonic waveguides. Phys. Rev. Lett. 93, 137404 (2004).

    Article  ADS  Google Scholar 

  25. Bouhelier, A., Beversluis, M., Hartschuh, A. & Novotny, L. Near-field second-harmonic generation induced by local field enhancement. Phys. Rev. Lett. 90, 013903 (2003).

    Article  ADS  Google Scholar 

  26. Ropers, C. et al. Grating-coupling of surface plasmons onto metallic tips: a nanoconfined light source. Nano Lett. 7, 2784–2788 (2007).

    Article  ADS  Google Scholar 

  27. Verhagen, E., Kuipers, L. & Polman, A. Enhanced nonlinear optical effects with a tapered plasmonic waveguide. Nano Lett. 7, 334–337 (2007).

    Article  ADS  Google Scholar 

  28. Lindquist, N. C., Nagpal, P., Lesuffleur, A., Norris, D. J. & Oh, S.-H. Three-dimensional plasmonic nanofocusing. Nano Lett. 10, 1369–1373 (2010).

    Article  ADS  Google Scholar 

  29. Verhagen, E., Polman, A. & Kuipers, L. (Kobus). Nanofocusing in laterally tapered plasmonic waveguides. Opt. Express 16, 45–57 (2008).

    Article  ADS  Google Scholar 

  30. Gramotnev, D. K., Vogel, M. W. & Stockman, M. I. Optimized nonadiabatic nanofocusing of plasmons by tapered metal rods. J. Appl. Phys. 104, 034311 (2008).

    Article  ADS  Google Scholar 

  31. Hecht, B. et al. Scanning near-field optical microscopy with aperture probes: fundamentals and applications. J. Chem. Phys. 112, 7761–7774 (2000).

    Article  ADS  Google Scholar 

  32. Novotny, L. & Hafner, C. Light propagation in a cylindrical waveguide with a complex, metallic dielectric function. Phys. Rev. E 50, 4094–4106 (1994).

    Article  ADS  Google Scholar 

  33. Issa, N. A. & Guckenberger, R. Optical nanofocusing on tapered metallic waveguides. Plasmonics 2, 31–37 (2007).

    Article  Google Scholar 

  34. Novotny, L. & Hecht, B. Principles of Nano-Optics (Cambridge Univ. Press, 2006).

    Book  Google Scholar 

  35. Vedantam, S. et al. A plasmonic dimple lens for nanoscale focusing of light. Nano Lett. 9, 3447–3452 (2009).

    Article  ADS  Google Scholar 

  36. Conway, J. Efficient Optical Coupling to the Nanoscale PhD thesis, Univ. California, (2006).

    Google Scholar 

  37. Worthing, P. T. & Barnes, W. L. Efficient coupling of surface plasmon polaritons to radiation using a bi-grating. Appl. Phys. Lett. 79, 3035–3037 (2001).

    Article  ADS  Google Scholar 

  38. Feng, N.-N. & Negro, L. D. Plasmon mode transformation in modulated-index metal–dielectric slot waveguides. Opt. Lett. 32, 3086–3088 (2007).

    Article  ADS  Google Scholar 

  39. Reuter, G. E. H. & Sondheimer, E. H. The theory of the anomalous skin effect in metals. Proc. R. Soc. Lond. A 195, 336–364 (1948).

    Article  ADS  Google Scholar 

  40. Schuck, P. J., Fromm, D. P., Sundaramurthy, A., Kino, G. S. & Moerner, W. E. Improving the mismatch between light and nanoscale objects with gold bowtie nanoantennas. Phys. Rev. Lett. 94, 017402 (2005).

    Article  ADS  Google Scholar 

  41. Beversluis, M. R., Bouhelier, A. & Novotny, L. Continuum generation from single gold nanostructures through near-field mediated intraband transitions. Phys. Rev. B 68, 115433 (2003).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

The authors thank X. Meng for gold evaporation and J. Dionne for her continuous encouragement. This work was supported by the Defense Advanced Research Project Agency (DARPA) Science & Technology (S&T) Surface-Enhanced Raman Scattering (SERS) programme, the Department of Energy (DOE), and the Engineering and Applied Sciences (EAS) division of California Institute of Technology.

Author information

Authors and Affiliations

Authors

Contributions

H.C. fabricated the 3D NPC devices, performed the experiments, and carried out TPPL measurements. S.C. and P.J.S. assisted with device fabrication and measurement collection. M.K. conducted the simulations and, with H.C., analysed the experimental data. M.S. and T.J.S. assisted with the simulations. J.B., M.W. and E.Y. provided in-depth discussion of the project. H.C. and M.K. wrote the manuscript.

Corresponding authors

Correspondence to Hyuck Choo or Eli Yablonovitch.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 2971 kb)

Supplementary Movie 1

Supplementary Movie 1 (WMV 6464 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Choo, H., Kim, MK., Staffaroni, M. et al. Nanofocusing in a metal–insulator–metal gap plasmon waveguide with a three-dimensional linear taper. Nature Photon 6, 838–844 (2012). https://doi.org/10.1038/nphoton.2012.277

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphoton.2012.277

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