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Thermal radiation scanning tunnelling microscopy

Abstract

In standard near-field scanning optical microscopy (NSOM), a subwavelength probe acts as an optical ‘stethoscope’ to map the near field produced at the sample surface by external illumination1. This technique has been applied using visible1,2, infrared3, terahertz4 and gigahertz5,6 radiation to illuminate the sample, providing a resolution well beyond the diffraction limit. NSOM is well suited to study surface waves such as surface plasmons7 or surface-phonon polaritons8. Using an aperture NSOM with visible laser illumination, a near-field interference pattern around a corral structure has been observed9, whose features were similar to the scanning tunnelling microscope image of the electronic waves in a quantum corral10. Here we describe an infrared NSOM that operates without any external illumination: it is a near-field analogue of a night-vision camera, making use of the thermal infrared evanescent fields emitted by the surface, and behaves as an optical scanning tunnelling microscope11,12. We therefore term this instrument a ‘thermal radiation scanning tunnelling microscope’ (TRSTM). We show the first TRSTM images of thermally excited surface plasmons, and demonstrate spatial coherence effects in near-field thermal emission.

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References

  1. 1

    Pohl, D. W., Denk, W. & Lanz, M. Optical stethoscopy: Image recording with resolution λ/20. Appl. Phys. Lett. 44, 651–653 (1984)

  2. 2

    Zenhausern, F., Martin, Y. & Wickramasinghe, H. K. Scanning apertureless microscopy: optical imaging at 10 Angstrom resolution. Science 269, 1083–1085 (1995)

  3. 3

    Lahrech, A., Bachelot, R., Gleyzes, P. & Boccara, A. C. Infrared-reflection-mode near-field microscopy using an apertureless probe with a resolution of λ/600. Opt. Lett. 21, 1315–1317 (1996)

  4. 4

    Chen, H-T., Kersting, R. & Cho, G. C. Terahertz imaging with nanometer resolution. Appl. Phys. Lett. 83, 309–311 (2003)

  5. 5

    Knoll, B., Keilmann, F., Kramer, A. & Guckenberger, R. Contrast of microwave near-field microscopy. Appl. Phys. Lett. 70, 2667–2669 (1997)

  6. 6

    Ash, E. A. & Nicholls, G. Super-resolution aperture scanning microscope. Nature 237, 510–512 (1972)

  7. 7

    Marti, O. et al. Near-field optical measurement of the surface plasmon field. Opt. Commun. 96, 225–228 (1993)

  8. 8

    Hillenbrand, R., Taubner, T. & Keilmann, F. Phonon-enhanced light–matter interaction at the nanometre scale. Nature 418, 159–161 (2002)

  9. 9

    Chicanne, C. et al. Imaging the local density of states of optical corrals. Phys. Rev. Lett. 88, 097402 (2002)

  10. 10

    Crommie, M. F., Lutz, C. P. & Eigler, D. M. Confinement of electrons to quantum corrals on a metal surface. Science 262, 218–220 (1993)

  11. 11

    Carminati, R. & Saenz, J. J. Scattering theory of Bardeen’s formalism for tunneling: New approach to near-field microscopy. Phys. Rev. Lett. 84, 5156–5159 (2000)

  12. 12

    Joulain, K., Carminati, R., Mulet, J-P. & Greffet, J-J. Definition and measurement of the local density of electromagnetic states close to an interface. Phys. Rev. B 68, 245405 (2003)

  13. 13

    De Wilde, Y., Formanek, F. & Aigouy, L. Apertureless near-field scanning optical microscope based on a quartz tuning fork. Rev. Sci. Instrum. 74, 3889–3891 (2003)

  14. 14

    Porto, J. A., Carminati, R. & Greffet, J-J. Theory of electromagnetic field imaging and spectroscopy in scanning near-field optical microscopy. J. Appl. Phys. 88, 4845–4850 (2000)

  15. 15

    Carminati, R. & Greffet, J-J. Near-field effects in spatial coherence of thermal sources. Phys. Rev. Lett. 82, 1660–1663 (1999)

  16. 16

    Greffet, J-J. et al. Coherent emission of light by thermal sources. Nature 416, 61–64 (2002)

  17. 17

    Kreiter, M. et al. Thermally induced emission of light from a metallic diffraction grating, mediated by surface plasmons. Opt. Commun. 168, 117–122 (1999)

  18. 18

    Shchegrov, A. V., Joulain, K., Carminati, R. & Greffet, J-J. Near-field spectral effects due to electromagnetic surface excitations. Phys. Rev. Lett. 85, 1548–1551 (2000)

  19. 19

    Hecht, B., Bielefeldt, H., Inouye, Y., Pohl, D. W. & Novotny, L. Facts and artifacts in near-field optical microscopy. J. Appl. Phys. 81, 2492–2498 (1997)

  20. 20

    Tersoff, J. & Hamann, D. R. Theory of the scanning tunneling microscope. Phys. Rev. B 31, 805–813 (1985)

  21. 21

    Agarwal, G. S. Quantum electrodynamics in the presence of dielectrics and conductors. IV General theory for spontaneous emission in finite geometries. Phys. Rev. A 12, 1475–1497 (1975)

  22. 22

    Gralak, B., de Dood, M. J. A., Tayeb, G., Enoch, S. & Maystre, D. Theoretical study of photonic band gaps in woodpile crystals. Phys. Rev. E 67, 066601 (2003)

  23. 23

    Knoll, B. & Keilmann, F. Enhanced dielectric contrast in scattering-type scanning near-field optical microscopy. Opt. Commun. 182, 321–328 (2000)

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Acknowledgements

We thank A.C. Boccara for comments and L. Aigouy for AFM measurements on the samples. This work was supported by the Ministère délégué à la Recherche (programme ACI Jeunes chercheurs) and the Centre National de la Recherche Scientifique.

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Correspondence to Yannick De Wilde.

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Further reading

Figure 1: Detection of the thermal radiation scanning tunnelling microscope (TRSTM) signal.
Figure 2: Analysing the origin of the TRSTM signal.
Figure 3: EM-LDOS measurement by TRSTM.
Figure 4: EM-LDOS images.

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