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Signal Analysis of Apertureless Scanning Near-Field Optical Microscopy with Superlens

By Chin-Ho Chuang and Yu-Lung Lo
Progress In Electromagnetics Research, Vol. 109, 83-106, 2010


Apertureless scanning near-field optical microscopy (A-SNOM) with a superlens is a novel nano-optical system for sub-wavelength imaging purposes. This study presents a quantitative model for analyzing the heterodyne signals obtained from an A-SNOM fitted with a superlens at various harmonics of the AFM tip vibration frequency. It is shown that the image resolution is determined not only by the tip radius, but also by the superlens transmission coefficient in the high evanescent wave vector Kx. Moreover, the analytical results show that the images acquired from the A-SNOM/superlens system are adversely affected by a signal contrast problem as a result of the noise generated by the tip-superlens interaction electric field. However, it is shown that this problem can be easily resolved using a background noise compensation method, thereby resulting in a significant improvement in the signal-to-background (S/B) ratio. The feasibility of utilizing the system for maskless nanolithography applications is discussed. It is shown that the A-SNOM/superlens system with the proposed noise compensation scheme yields a dramatic improvement in the signal intensity and S/B ratio compared to that of a conventional A-SNOM with a bare tip only.


Chin-Ho Chuang and Yu-Lung Lo, "Signal Analysis of Apertureless Scanning Near-Field Optical Microscopy with Superlens," Progress In Electromagnetics Research, Vol. 109, 83-106, 2010.


    1. Betzig, E. and M. Isaacson, "Collection mode near-field scanning optical microscopy," Appl. Phys. Lett., Vol. 51, 2088-2090, 1987.

    2. Betzig, E., J. K. Trautman, T. D. Harris, J. S. Weiner, and R. L. Kostelak, "Breaking the diffraction barrier-optical microscopy on a nanometric scale," Science, Vol. 251, 1468-1470, 1991.

    3. Kirstein, S., "Scanning near-field optical microscopy," Current Opinion in Colloid & Interface Science, Vol. 4, 256-264, 1999.

    4. Hillenbrand, R. and F. Keilmann, "Complex optical constants on a subwavelength scale," Phys. Rev. Lett., Vol. 85, 3029-3032, 2000.

    5. Knoll, B. and F. Keilmann, "Enhanced dielectric contrast in scattering-type scanning near-field optical microscopy," Opt. Commun., Vol. 182, 321-328, 2000.

    6. Hillenbrand, R., T. Taubner, and F. Keilmann , "Phonon-enhanced light-matter interaction at the nanometer scale," Nature, Vol. 418, 159-162, 2002.

    7. Novotny, L., E. Z. Sanchez, and X. S. Xie, "Near-field optical imaging using metal tips illuminated by higher-order Hermite-Gaussian beams," Ultramicrosc, Vol. 71, 21-29, 1998.

    8. Pendry, J. B., "Negative refraction makes a perfect lens," Phys. Rev. Lett., Vol. 85, 3966-3969, 2000.

    9. Smith, D. R., J. B. Pendry, and M. C. K. Wiltshire, "Metamaterial and negative refractive index," Science, Vol. 305, 788-792, 2004.

    10. Shalaev, V. M., "Optical negative-index metamaterials," Nat. Photonics, Vol. 1, 41-48, 2007.

    11. Wang, G., Y. Gong, and H. Wang, "On the size of left-handed material lens for near-fid target detection by focus scanning," Progress In Electromagnetics Research, Vol. 87, 345-361, 2008.

    12. Wang, R., J. Zhou, C. Sun, L. Kang, Q. Zhao, and J. Sun, "Left-handed materials based on crystal lattice vibration," Progress In Electromagnetics Research Letters, Vol. 10, 145-155, 2009.

    13. Srivastava, R., S. Srivastava, and S. P. Ojha, "Negative refraction by photonic crystal," Progress In Electromagnetics Research B, Vol. 2, 15-26, 2008.

    14. Fang, N., Z. Liu, T. J. Yen, and X. Zhang, "Regenerating evanescent waves from a silver superlens," Opt. Express, Vol. 11, 682-687, 2003.

    15. Fang, N., H. Lee, C. Sun, and X. Zhang, "Sub-diffraction-limited optical imaging with a silver superlens," Science, Vol. 308, 534-537, 2005.

    16. Taubner, T., D. Korobkin, Y. Urzhumov, G. Shvet, and R. Hillenbrand, "Near-field microscopy through a SiC superlens," Science, Vol. 313, 1595, 2006.

    17. Chuang, C. H. and Y. L. Lo, "Analytical analysis of modulated signal in apertureless scanning near-field optical microscopy," Opt. Express, Vol. 15, 15782-15796, 2007.

    18. Chuang, C. H. and Y. L. Lo, "An analysis of heterodyne signals in apertureless scanning near-field optical microscopy," Opt. Express, Vol. 16, 17982-18003, 2008.

    19. Podolskiy, V. A. and E. E. Narimanov, "Near-sighted superlens," Opt. Lett., Vol. 30, 75-77, 2005.

    20. Ocelic, N., A. Huber, and R. Hillenbrand, "Pseudoheterodyne detection for background-free near-field spectroscopy," Appl. Phys. Lett., Vol. 89, 101124, 2006.

    21. Sun, J., P. S. Carney, and J. C. Schotland, "Strong tip effect near-field scanning optical tomography," J. Appl. Phys., Vol. 102, 103103, 2007.

    22. Jackson, J. D., Classical Electrodynamics, Wiley, 1999.

    23. Lee, K., H. Park, J. Kim, G. Kang, and K. Kim, "Improved image quality of a Ag slab near-field superlens with intrinsic loss of absorption," Opt. Express, Vol. 16, 1711-1718, 2008.

    24. Fujii, M., W. Freude, and J. Leuthold, "Numerical prediction of minimum sub-diffraction-limit image generated by silver surface plasmon lenses," Opt. Express, Vol. 16, 21039-21052, 2008.

    25. Veselago, V., L. Braginsky, V. Shklover, and C. Hafner, "Negative refractive index materials," J. Comput. Theor. Nanosci., Vol. 3, 1-30, 2006.

    26. Korobkin, D., Y. Urzhumov, and G. Shvet, "Enhanced near-field resolution in midinfrared using metamaterials," J. Opt. Soc. Am. B, Vol. 23, 468-478, 2006.

    27. Smith, D. R., D. S. Schurig, M. Rosenbluth, S. Schultz, S. A. Ramarkrishna, and J. B. Pendry, "Limitations on sub diffraction imaging with a negative index slab," Appl. Phys. Lett., Vol. 82, 1506-1508, 2003.

    28. Stefanon, I., S. Blaize, A. Bruyant, S Aubert, G. Lerondel, R. Bachelot, and P. Royer, "Heterodyne detection of guided waves using a scattering-type scanning near-field optical microscope," Opt. Express, Vol. 13, 5553-5564, 2005.

    29. Lo, Y. L. and C. H. Chuang, "New synthetic-heterodyne demodulation for an optical fiber interferometry," J. Quantum Electron., Vol. 37, 658-663, 2001.

    30. Walford, J. N., J. A. Porto, R. Carminati, J. J. Greffet, P. M. Adam, S. Hudlet, J. L. Bijeon, A. Stashkevich, and P. Royer, "Influence of tip modulation on image formation in scanning near-field optical microscopy," J. Appl. Phys., Vol. 89, 5159-5169, 2001.

    31. Bortchagovsky, E. G., "Superlens approach to a long-focus near-field probe," Opt. Lett., Vol. 33, 1765-1767, 2008.

    32. H'dhili, F., R. Bachelot, G. Lerondel, D. Barchiesi, and P. Royer, "Near-field optics: Direct observation of the field enhancement below an apertureless probe using a photosensitive polymer," Appl. Phys. Lett., Vol. 79, 4019-4021, 2001.

    33. Tseng, A. A., "Recent developments in nanofabrication using scanning near-field optical microscope lithography," Opt. Laser Technol., Vol. 39, 514-526, 2007.