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.

Silicon nanostructure cloak operating at optical frequencies

Nature Photonics volume 3, pages 461–463 (2009)Cite this article

Abstract

The ability to render objects invisible using a cloak (such that they are not detectable by an external observer) has long been a tantalizing goal1,2,3,4,5,6. Here, we demonstrate a cloak operating in the near infrared at a wavelength of 1,550 nm. The cloak conceals a deformation on a flat reflecting surface, under which an object can be hidden. The device has an area of 225 µm2 and hides a region of 1.6 µm2. It is composed of nanometre-size silicon structures with spatially varying densities across the cloak. The density variation is defined using transformation optics to define the effective index distribution of the cloak.

This is a preview of subscription content

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

Buy

All prices are NET prices.

Figure 1: Cloaking principle of the fabricated device.
Figure 2: Scanning electron microscope images of the cloaking device.
Figure 3: Two-dimensional spatial effective refractive index distribution of the cloaking device.
Figure 4: Simulations of the cloaking device.
Figure 5: Output images from the fabricated devices, tested by launching light with a wavelength of 1,550 nm into the waveguide and imaging the edge of the device (dashed lines).

References

  1. Alú, A. & Engheta, N. Achieving transparency with plasmonic and metamaterial coatings. Phys. Rev. E 72, 016623 (2005).

    ADS  Article  Google Scholar 

  2. Miller, D. A. B. On perfect cloaking. Opt. Express 14, 12457–12466 (2006).

    ADS  Article  Google Scholar 

  3. Alú, A. & Engheta, N. Plasmonic materials in transparency and cloaking problems: mechanism, robustness and physical insights. Opt. Express 15, 3318–3332 (2007).

    ADS  Article  Google Scholar 

  4. Zhao, Y., Argyropoulos, C. & Hao, Y. Full-wave finite-difference time-domain simulation of electromagnetic cloaking structures. Opt. Express 16, 6717–6730 (2008).

    ADS  Article  Google Scholar 

  5. Weder, R. A rigorous analysis of high-order electromagnetic invisibility cloaks. J. Phys. A 41, 065207 (2008).

    ADS  MathSciNet  Article  Google Scholar 

  6. Weder, R. The boundary conditions for point transformed electromagnetic invisibility cloaks. J. Phys. A 41, 415401 (2008).

    MathSciNet  Article  Google Scholar 

  7. Ward, A. & Pendry, J. Refraction and geometry in Maxwell's equations. J. Mod. Opt. 43, 773–793 (1996).

    ADS  MathSciNet  Article  Google Scholar 

  8. Leonhardt, U. & Philbin, T. G. General relativity in electrical engineering. New J. Phys. 8, 247 (2006).

    ADS  Article  Google Scholar 

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

    ADS  MathSciNet  Article  Google Scholar 

  10. Kildishev, A. V. & Shalaev, V. M. Engineering space for light via transformation optics. Opt. Lett. 33, 43–45 (2008).

    ADS  Article  Google Scholar 

  11. Tyc, T. & Leonhardt, U. Transmutation of singularities in optical instruments. New J. Phys. 10, 115038 (2008).

    ADS  Article  Google Scholar 

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

    ADS  MathSciNet  Article  Google Scholar 

  13. Cummer, S. A., Popa, B., Schurig, D., Smith, D. R. & Pendry, J. Full-wave simulations of electromagnetic cloaking structures. Phys. Rev. E 74, 036621 (2006).

    ADS  Article  Google Scholar 

  14. Hendi, A., Henn, J. & Leonhardt, U. Ambiguities in the scattering tomography for central potentials. Phys. Rev. Lett. 97, 073902 (2006).

    ADS  Article  Google Scholar 

  15. Cai, W., Chettiar, U. K., Kildishev, A. V. & Shalaev, V. M. Optical cloaking with metamaterials. Nature Photon. 1, 224–227 (2007).

    ADS  Article  Google Scholar 

  16. Ruan, Z., Yan, M., Neff, C. W. & Qiu, M. Ideal cylindrical cloak: perfect but sensitive to tiny perturbations. Phys. Rev. Lett. 99, 113903 (2007).

    ADS  Article  Google Scholar 

  17. Chen, H., Wu, B., Zhang, B. & Kong, J. A. Electromagnetic wave interactions with a metamaterial cloak. Phys. Rev. Lett. 99, 063903 (2007).

    ADS  Article  Google Scholar 

  18. Huang, Y., Feng, Y. & Jiang, T. Electromagnetic cloaking by layered structure of homogeneous isotropic materials. Opt. Express 15, 11133–11141 (2007).

    ADS  Article  Google Scholar 

  19. Silveirinha, M. G., Alu, A. & Engheta, N. Parallel-plate metamaterials for cloaking structures. Phys. Rev. E 75, 036603 (2007).

    ADS  Article  Google Scholar 

  20. Li, J. & Pendry, J. B. Hiding under the carpet: a new strategy for cloaking. Phys. Rev. Lett. 101, 203901 (2008).

    ADS  Article  Google Scholar 

  21. Alú, A. & Engheta, N. Multifrequency optical invisibility cloak with layered plasmonic shells. Phys. Rev. Lett. 100, 113901 (2008).

    ADS  Article  Google Scholar 

  22. Jiang, W. X. et al. Analytical design of conformally invisible cloaks for arbitrarily shaped objects. Phys. Rev. E 77, 066607 (2008).

    ADS  Article  Google Scholar 

  23. Leonhardt, U. & Tyc, T. Broadband invisibility by non-Euclidean cloaking. Science 323, 110–112 (2009).

    ADS  Article  Google Scholar 

  24. Schurig, D. et al. Metamaterial electromagnetic cloak at microwave frequencies. Science 314, 977–980 (2006).

    ADS  MathSciNet  Article  Google Scholar 

  25. Liu, R. et al. Broadband ground-plane cloak. Science 323, 366–369 (2009).

    ADS  Article  Google Scholar 

  26. Valentine, J., Li, J., Zentgraf, T., Bartal, G. & Zhang, X. An optical cloak made of dielectrics. Nature Mater. 8, 569–571 (2009).

    ADS  Article  Google Scholar 

  27. Nakamura, T., Shimizu, M., Kimura, H. & Sato, R. Effective permittivity of amorphous mixed materials. Electron. Commun. Jpn. 1 88, 1–9 (2005).

    Google Scholar 

  28. Knupp, P. M. & Steinberg, S. Fundamentals of Grid Generation (CRC Press, 1993).

    MATH  Google Scholar 

  29. Thompson, J. F., Soni, B. K. & Weatherill, N. P. Handbook of Grid Generation (CRC Press, 1998).

    MATH  Google Scholar 

  30. Shalaev, V. M. Physics: transforming light. Science 322, 384–386 (2008).

    Article  Google Scholar 

Download references

Acknowledgements

The authors would like to acknowledge the support of Cornell's Center for Nanoscale Systems (CNS), funded by the National Science Foundation. This work was performed in part at the Cornell Nanoscale Facility, a member of the National Nanotechnology Infrastructure Network, which is supported by the National Science Foundation.

Author information

Authors and Affiliations

  1. Nanophotonics Group, School of Electrical and Computer Engineering, 209 Phillips Hall

    Lucas H. Gabrielli & Jaime Cardenas

  2. Cornell University, Ithaca, 14853, New York, USA

    Lucas H. Gabrielli & Jaime Cardenas

  3. Nanophotonics Group, School of Electrical and Computer Engineering, 211 Phillips Hall

    Carl B. Poitras

  4. Cornell University, Ithaca, 14853, New York, USA

    Carl B. Poitras

  5. Nanophotonics Group, School of Electrical and Computer Engineering, 214 Phillips Hall

    Michal Lipson

  6. Cornell University, Ithaca, 14853, New York, USA

    Michal Lipson

Authors
  1. Lucas H. Gabrielli
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Jaime Cardenas
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Carl B. Poitras
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Michal Lipson
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

L.H.G. designed and simulated the devices. L.H.G. and J.C. carried out the fabrication of the samples. L.H.G. and C.B.P. conducted the experiments. L.H.G., C.B.P. and M.L. designed the experiments and discussed their results and implications.

Corresponding author

Correspondence to Michal Lipson.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Gabrielli, L., Cardenas, J., Poitras, C. et al. Silicon nanostructure cloak operating at optical frequencies. Nature Photon 3, 461–463 (2009). https://doi.org/10.1038/nphoton.2009.117

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nphoton.2009.117

Further reading

Search

Advanced 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