Abstract

Optical-field enhancement and confinement for an asymmetrically illuminated nanoscopic Au tip suspended over a planar Au substrate is investigated both numerically and experimentally. The spatial field distribution of the tip-sample system was calculated using the full 3D finite-difference time-domain method. The calculation enables investigation of the effects of the substrate-tip placement, angle of incidence, and spectral response. The tip plasmon response leads to a significant (up to ~70 times) local field enhancement between the tip and substrate. The enhancement is found to be extremely sensitive to the tip-sample separation distance. Tip-enhanced Raman scattering experiments were performed and the numerical results provide a consistent description of the observed field localization and enhancement.

© 2006 Optical Society of America

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    [CrossRef]
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2005 (9)

C. C. Neacsu, G. A. Steudle, M. B. Raschke, "Plasmonic light scattering from nanoscopic metal tips," Appl. Phys. B 80, 295-300 (2005).
[CrossRef]

A. L. Demming, F. Festy, and D. Richards, "Plasmon resonances on metal tips: Understanding tip-enhanced Raman scattering," J. Chem. Phys. 122, 184716 (2005).
[CrossRef] [PubMed]

C. C. Neacsu, G. A. Reider, and M. B. Raschke, "Second-harmonic generation from nanoscopic metal tips: Symmetry selection rules for single asymmetric nanostructures," Phys. Rev. B 71, 201402 (2005).
[CrossRef]

S. Bruzzone, M. Malvaldi, G. Arrighini, and C. Guidotti, "Theoretical Study of Electromagnetic Scattering by Metal Nanoparticles," J. Phys. Chem. B 109, 3807-3812 (2005).
[CrossRef]

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, andW. E.Moerner, "Improving theMismatch between Light and Nanoscale Objects with Gold Bowtie Nanoantennas," Phys. Rev. Lett. 94, 017402 (2005).
[CrossRef] [PubMed]

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, "Resonant Optical Antennas," Science 308, 1607-1609 (2005).
[CrossRef] [PubMed]

A. D. McFarland, M. A. Young, J. Dieringer, R. P. Van Duyne, "Wavelength-Scanned Surface Enhanced Raman Excitation Spectroscopy," J. Phys. Chem. B 109, 11279 (2005).
[CrossRef]

L. Liu, and S. He, "Design of metal-cladded near-field fiber probes with a dispersive body-of-revolution finitedifference time-domain method," Appl. Opt. 44, 3429-3437 (2005).
[CrossRef] [PubMed]

T.-W. Lee and S. K. Gray, "Subwavelength light bending by metal slit structures," Opt. Express 13, 9652-9659 (2005).
[CrossRef] [PubMed]

2004 (5)

M. I. Stockman, "Nanofocusing of Optical Energy in Tapered Plasmonic Waveguides," Phys. Rev. Lett. 93, 137404 (2004).
[CrossRef] [PubMed]

A. Bouhelier, M. R. Beversluis, and L. Novotny, "Applications of field-enhanced near-field optical microscopy," Ultramicroscopy 100, 413-419 (2004).
[CrossRef] [PubMed]

F. Keilmann and R. Hillenbrand, "Near-field microscopy by elastic light scattering from a tip," Phil. Trans. R. Soc. Lond. A 362, 787-805 (2004).
[CrossRef]

T. Ichimura, N. Hayazawa, M. Hashimoto, Y. Inouye, and S. Kawata, S. "Tip-Enhanced Coherent Anti-Stokes Raman Scattering for Vibrational Nanoimaging," Phys. Rev. Lett. 92, 220801 (2004).
[CrossRef] [PubMed]

N.-C. Panoiu and R. M. Osgood, Jr., "Subwavelength Nonlinear Plasmonic Nanowire," Nano Lett. 4, 2427-2430 (2004).
[CrossRef]

2003 (5)

A. Bouhelier, M. Beversluis, A. Hartschuh, and L. Novotny, "Near-field Second-Harmonic Generation Induced by Local Field Enhancement," Phys. Rev. Lett. 90, 013903 (2003).
[CrossRef] [PubMed]

A. Hartschuh, E. J. Sanchez, X. S. Xie, and L. Novotny, "High-Resolution Near-Field Raman Microscopy of Single-Walled Carbon Nanotubes," Phys. Rev. Lett. 90, 095503 (2003).
[CrossRef] [PubMed]

J. A. Porto, P. Johansson, S. P. Apell, and T. Lopez-Rios, "Resonance shift effects in apertureless scanning near-field optical microscopy," Phys. Rev. B 67, 085409 (2003).
[CrossRef]

C. L. Haynes and R. P. Van Duyne, "Plasmon-Sampled Surface-Enhanced Raman Excitation Spectroscopy," J. Phys. Chem. B 107, 7426-7433 (2003).
[CrossRef]

J. L. West and N. J. Halas, "Engineered Nanomaterials for Biophotonics Applications: Improving Sensing, Imaging, and Therapeutics," Ann. Rev. Biomed. Eng. 5, 285-292 (2003).
[CrossRef]

2002 (3)

A. Bouhelier, J. Renger, M.-R. Beversluis, and L. Novotny, "Plasmon-coupled tip-enhanced near-field optical microscopy," J. Microscopy 210, 220-224 (2002).
[CrossRef]

J. T. Krug, E. J. Sanchez, and S. Xie, "Design of near-field optical probes with optimal field enhancement by finite difference time domain electromagnetic simulation," J. Chem. Phys. 116, 10895-10901 (2002).
[CrossRef]

N. Nilius, N. Ernst, and H.-J. Freund, "Tip influence on plasmon exicitations in single gold particles in an STM," Phys. Rev. B 65, 115421 (2002).
[CrossRef]

2001 (1)

T. Ito and K. Sakoda, "Photonic bands of metallic systems. II. Features of surface plasmon polaritons," Phys. Rev. B 64, 045117 (2001).
[CrossRef]

2000 (2)

K. Karrai, I. Tiemann, "Interfacial shear force microscopy," Phys. Rev. B 68, 13174 (2000).
[CrossRef]

L. Aigouy, F. X. Andreani, A. C. Boccara, J. C. Rivoal, J. A. Porto, R. Carminati, J.-J. Greffet, and R. Megy, "Near-field optical spectroscopy using an incoherent light source," Appl. Phys. Lett. 76, 397-399 (2000).
[CrossRef]

1999 (1)

Y. Kawata, C. Xu, and W. Denk, "Feasibility of molecular-resolution fluorescence near-field microscopy using multi-photon absorption and field enhancement near a sharp tip," J. Appl. Phys. 85, 1294-1301 (1999).
[CrossRef]

1997 (3)

S. Nie and S.-R. Emory, "Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering," Science 275, 1102-1106 (1997).
[CrossRef] [PubMed]

K. Kneipp, Y. Wang, H. Kneipp, L. T. Perelman, I. Itzkan, R. R. Dasari, and M. S. Feld, "Single-Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)," Phys. Rev. Lett. 78, 1667-1670 (1997).
[CrossRef]

V. Kuzmiak, A. A. Maradudin, "Photonic band structures of one- and two-dimensional periodic systems with metallic components in the presence of dissipation," Phys. Rev. B 55, 7427-7444 (1997).
[CrossRef]

1991 (1)

W. Denk, and D. W. Pohl, "Near-field optics: Microscopy with nanometer-size fields," J. Vac. Sci. Technol. B 9, 510-513 (1991).
[CrossRef]

1985 (2)

1983 (1)

C. J. Chen and R. M. Osgood, "Direct Observation of the Local-Field-Enhanced Surface Photochemical Reactions," Phys. Rev. Lett. 50, 1705-1708 (1983).
[CrossRef]

Aigouy, L.

L. Aigouy, F. X. Andreani, A. C. Boccara, J. C. Rivoal, J. A. Porto, R. Carminati, J.-J. Greffet, and R. Megy, "Near-field optical spectroscopy using an incoherent light source," Appl. Phys. Lett. 76, 397-399 (2000).
[CrossRef]

Alexander, R. W.

Andreani, F. X.

L. Aigouy, F. X. Andreani, A. C. Boccara, J. C. Rivoal, J. A. Porto, R. Carminati, J.-J. Greffet, and R. Megy, "Near-field optical spectroscopy using an incoherent light source," Appl. Phys. Lett. 76, 397-399 (2000).
[CrossRef]

Apell, S. P.

J. A. Porto, P. Johansson, S. P. Apell, and T. Lopez-Rios, "Resonance shift effects in apertureless scanning near-field optical microscopy," Phys. Rev. B 67, 085409 (2003).
[CrossRef]

Arrighini, G.

S. Bruzzone, M. Malvaldi, G. Arrighini, and C. Guidotti, "Theoretical Study of Electromagnetic Scattering by Metal Nanoparticles," J. Phys. Chem. B 109, 3807-3812 (2005).
[CrossRef]

Bell, R. J.

Beversluis, M.

A. Bouhelier, M. Beversluis, A. Hartschuh, and L. Novotny, "Near-field Second-Harmonic Generation Induced by Local Field Enhancement," Phys. Rev. Lett. 90, 013903 (2003).
[CrossRef] [PubMed]

Beversluis, M. R.

A. Bouhelier, M. R. Beversluis, and L. Novotny, "Applications of field-enhanced near-field optical microscopy," Ultramicroscopy 100, 413-419 (2004).
[CrossRef] [PubMed]

Beversluis, M.-R.

A. Bouhelier, J. Renger, M.-R. Beversluis, and L. Novotny, "Plasmon-coupled tip-enhanced near-field optical microscopy," J. Microscopy 210, 220-224 (2002).
[CrossRef]

Boccara, A. C.

L. Aigouy, F. X. Andreani, A. C. Boccara, J. C. Rivoal, J. A. Porto, R. Carminati, J.-J. Greffet, and R. Megy, "Near-field optical spectroscopy using an incoherent light source," Appl. Phys. Lett. 76, 397-399 (2000).
[CrossRef]

Bouhelier, A.

A. Bouhelier, M. R. Beversluis, and L. Novotny, "Applications of field-enhanced near-field optical microscopy," Ultramicroscopy 100, 413-419 (2004).
[CrossRef] [PubMed]

A. Bouhelier, M. Beversluis, A. Hartschuh, and L. Novotny, "Near-field Second-Harmonic Generation Induced by Local Field Enhancement," Phys. Rev. Lett. 90, 013903 (2003).
[CrossRef] [PubMed]

A. Bouhelier, J. Renger, M.-R. Beversluis, and L. Novotny, "Plasmon-coupled tip-enhanced near-field optical microscopy," J. Microscopy 210, 220-224 (2002).
[CrossRef]

Bruzzone, S.

S. Bruzzone, M. Malvaldi, G. Arrighini, and C. Guidotti, "Theoretical Study of Electromagnetic Scattering by Metal Nanoparticles," J. Phys. Chem. B 109, 3807-3812 (2005).
[CrossRef]

Carminati, R.

L. Aigouy, F. X. Andreani, A. C. Boccara, J. C. Rivoal, J. A. Porto, R. Carminati, J.-J. Greffet, and R. Megy, "Near-field optical spectroscopy using an incoherent light source," Appl. Phys. Lett. 76, 397-399 (2000).
[CrossRef]

Chen, C. J.

C. J. Chen and R. M. Osgood, "Direct Observation of the Local-Field-Enhanced Surface Photochemical Reactions," Phys. Rev. Lett. 50, 1705-1708 (1983).
[CrossRef]

Dasari, R. R.

K. Kneipp, Y. Wang, H. Kneipp, L. T. Perelman, I. Itzkan, R. R. Dasari, and M. S. Feld, "Single-Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)," Phys. Rev. Lett. 78, 1667-1670 (1997).
[CrossRef]

Demming, A. L.

A. L. Demming, F. Festy, and D. Richards, "Plasmon resonances on metal tips: Understanding tip-enhanced Raman scattering," J. Chem. Phys. 122, 184716 (2005).
[CrossRef] [PubMed]

Denk, W.

Y. Kawata, C. Xu, and W. Denk, "Feasibility of molecular-resolution fluorescence near-field microscopy using multi-photon absorption and field enhancement near a sharp tip," J. Appl. Phys. 85, 1294-1301 (1999).
[CrossRef]

W. Denk, and D. W. Pohl, "Near-field optics: Microscopy with nanometer-size fields," J. Vac. Sci. Technol. B 9, 510-513 (1991).
[CrossRef]

Dieringer, J.

A. D. McFarland, M. A. Young, J. Dieringer, R. P. Van Duyne, "Wavelength-Scanned Surface Enhanced Raman Excitation Spectroscopy," J. Phys. Chem. B 109, 11279 (2005).
[CrossRef]

Eisler, H.-J.

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, "Resonant Optical Antennas," Science 308, 1607-1609 (2005).
[CrossRef] [PubMed]

Emory, S.-R.

S. Nie and S.-R. Emory, "Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering," Science 275, 1102-1106 (1997).
[CrossRef] [PubMed]

Ernst, N.

N. Nilius, N. Ernst, and H.-J. Freund, "Tip influence on plasmon exicitations in single gold particles in an STM," Phys. Rev. B 65, 115421 (2002).
[CrossRef]

Feld, M. S.

K. Kneipp, Y. Wang, H. Kneipp, L. T. Perelman, I. Itzkan, R. R. Dasari, and M. S. Feld, "Single-Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)," Phys. Rev. Lett. 78, 1667-1670 (1997).
[CrossRef]

Festy, F.

A. L. Demming, F. Festy, and D. Richards, "Plasmon resonances on metal tips: Understanding tip-enhanced Raman scattering," J. Chem. Phys. 122, 184716 (2005).
[CrossRef] [PubMed]

Freund, H.-J.

N. Nilius, N. Ernst, and H.-J. Freund, "Tip influence on plasmon exicitations in single gold particles in an STM," Phys. Rev. B 65, 115421 (2002).
[CrossRef]

Fromm, D. P.

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, andW. E.Moerner, "Improving theMismatch between Light and Nanoscale Objects with Gold Bowtie Nanoantennas," Phys. Rev. Lett. 94, 017402 (2005).
[CrossRef] [PubMed]

Gray, S. K.

Greffet, J.-J.

L. Aigouy, F. X. Andreani, A. C. Boccara, J. C. Rivoal, J. A. Porto, R. Carminati, J.-J. Greffet, and R. Megy, "Near-field optical spectroscopy using an incoherent light source," Appl. Phys. Lett. 76, 397-399 (2000).
[CrossRef]

Guidotti, C.

S. Bruzzone, M. Malvaldi, G. Arrighini, and C. Guidotti, "Theoretical Study of Electromagnetic Scattering by Metal Nanoparticles," J. Phys. Chem. B 109, 3807-3812 (2005).
[CrossRef]

Halas, N. J.

J. L. West and N. J. Halas, "Engineered Nanomaterials for Biophotonics Applications: Improving Sensing, Imaging, and Therapeutics," Ann. Rev. Biomed. Eng. 5, 285-292 (2003).
[CrossRef]

Hartschuh, A.

A. Hartschuh, E. J. Sanchez, X. S. Xie, and L. Novotny, "High-Resolution Near-Field Raman Microscopy of Single-Walled Carbon Nanotubes," Phys. Rev. Lett. 90, 095503 (2003).
[CrossRef] [PubMed]

A. Bouhelier, M. Beversluis, A. Hartschuh, and L. Novotny, "Near-field Second-Harmonic Generation Induced by Local Field Enhancement," Phys. Rev. Lett. 90, 013903 (2003).
[CrossRef] [PubMed]

Hashimoto, M.

T. Ichimura, N. Hayazawa, M. Hashimoto, Y. Inouye, and S. Kawata, S. "Tip-Enhanced Coherent Anti-Stokes Raman Scattering for Vibrational Nanoimaging," Phys. Rev. Lett. 92, 220801 (2004).
[CrossRef] [PubMed]

Hayazawa, N.

T. Ichimura, N. Hayazawa, M. Hashimoto, Y. Inouye, and S. Kawata, S. "Tip-Enhanced Coherent Anti-Stokes Raman Scattering for Vibrational Nanoimaging," Phys. Rev. Lett. 92, 220801 (2004).
[CrossRef] [PubMed]

Haynes, C. L.

C. L. Haynes and R. P. Van Duyne, "Plasmon-Sampled Surface-Enhanced Raman Excitation Spectroscopy," J. Phys. Chem. B 107, 7426-7433 (2003).
[CrossRef]

He, S.

Hecht, B.

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, "Resonant Optical Antennas," Science 308, 1607-1609 (2005).
[CrossRef] [PubMed]

Hillenbrand, R.

F. Keilmann and R. Hillenbrand, "Near-field microscopy by elastic light scattering from a tip," Phil. Trans. R. Soc. Lond. A 362, 787-805 (2004).
[CrossRef]

Ichimura, T.

T. Ichimura, N. Hayazawa, M. Hashimoto, Y. Inouye, and S. Kawata, S. "Tip-Enhanced Coherent Anti-Stokes Raman Scattering for Vibrational Nanoimaging," Phys. Rev. Lett. 92, 220801 (2004).
[CrossRef] [PubMed]

Inouye, Y.

T. Ichimura, N. Hayazawa, M. Hashimoto, Y. Inouye, and S. Kawata, S. "Tip-Enhanced Coherent Anti-Stokes Raman Scattering for Vibrational Nanoimaging," Phys. Rev. Lett. 92, 220801 (2004).
[CrossRef] [PubMed]

Ito, T.

T. Ito and K. Sakoda, "Photonic bands of metallic systems. II. Features of surface plasmon polaritons," Phys. Rev. B 64, 045117 (2001).
[CrossRef]

Itzkan, I.

K. Kneipp, Y. Wang, H. Kneipp, L. T. Perelman, I. Itzkan, R. R. Dasari, and M. S. Feld, "Single-Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)," Phys. Rev. Lett. 78, 1667-1670 (1997).
[CrossRef]

Johansson, P.

J. A. Porto, P. Johansson, S. P. Apell, and T. Lopez-Rios, "Resonance shift effects in apertureless scanning near-field optical microscopy," Phys. Rev. B 67, 085409 (2003).
[CrossRef]

Karrai, K.

K. Karrai, I. Tiemann, "Interfacial shear force microscopy," Phys. Rev. B 68, 13174 (2000).
[CrossRef]

Kawata, S.

T. Ichimura, N. Hayazawa, M. Hashimoto, Y. Inouye, and S. Kawata, S. "Tip-Enhanced Coherent Anti-Stokes Raman Scattering for Vibrational Nanoimaging," Phys. Rev. Lett. 92, 220801 (2004).
[CrossRef] [PubMed]

Kawata, Y.

Y. Kawata, C. Xu, and W. Denk, "Feasibility of molecular-resolution fluorescence near-field microscopy using multi-photon absorption and field enhancement near a sharp tip," J. Appl. Phys. 85, 1294-1301 (1999).
[CrossRef]

Keilmann, F.

F. Keilmann and R. Hillenbrand, "Near-field microscopy by elastic light scattering from a tip," Phil. Trans. R. Soc. Lond. A 362, 787-805 (2004).
[CrossRef]

Kino, G. S.

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, andW. E.Moerner, "Improving theMismatch between Light and Nanoscale Objects with Gold Bowtie Nanoantennas," Phys. Rev. Lett. 94, 017402 (2005).
[CrossRef] [PubMed]

Kneipp, H.

K. Kneipp, Y. Wang, H. Kneipp, L. T. Perelman, I. Itzkan, R. R. Dasari, and M. S. Feld, "Single-Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)," Phys. Rev. Lett. 78, 1667-1670 (1997).
[CrossRef]

Kneipp, K.

K. Kneipp, Y. Wang, H. Kneipp, L. T. Perelman, I. Itzkan, R. R. Dasari, and M. S. Feld, "Single-Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)," Phys. Rev. Lett. 78, 1667-1670 (1997).
[CrossRef]

Krug, J. T.

J. T. Krug, E. J. Sanchez, and S. Xie, "Design of near-field optical probes with optimal field enhancement by finite difference time domain electromagnetic simulation," J. Chem. Phys. 116, 10895-10901 (2002).
[CrossRef]

Kuzmiak, V.

V. Kuzmiak, A. A. Maradudin, "Photonic band structures of one- and two-dimensional periodic systems with metallic components in the presence of dissipation," Phys. Rev. B 55, 7427-7444 (1997).
[CrossRef]

Lee, T.-W.

Liu, L.

Long, L. L.

Lopez-Rios, T.

J. A. Porto, P. Johansson, S. P. Apell, and T. Lopez-Rios, "Resonance shift effects in apertureless scanning near-field optical microscopy," Phys. Rev. B 67, 085409 (2003).
[CrossRef]

Malvaldi, M.

S. Bruzzone, M. Malvaldi, G. Arrighini, and C. Guidotti, "Theoretical Study of Electromagnetic Scattering by Metal Nanoparticles," J. Phys. Chem. B 109, 3807-3812 (2005).
[CrossRef]

Maradudin, A. A.

V. Kuzmiak, A. A. Maradudin, "Photonic band structures of one- and two-dimensional periodic systems with metallic components in the presence of dissipation," Phys. Rev. B 55, 7427-7444 (1997).
[CrossRef]

Martin, O. J. F.

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, "Resonant Optical Antennas," Science 308, 1607-1609 (2005).
[CrossRef] [PubMed]

McFarland, A. D.

A. D. McFarland, M. A. Young, J. Dieringer, R. P. Van Duyne, "Wavelength-Scanned Surface Enhanced Raman Excitation Spectroscopy," J. Phys. Chem. B 109, 11279 (2005).
[CrossRef]

Megy, R.

L. Aigouy, F. X. Andreani, A. C. Boccara, J. C. Rivoal, J. A. Porto, R. Carminati, J.-J. Greffet, and R. Megy, "Near-field optical spectroscopy using an incoherent light source," Appl. Phys. Lett. 76, 397-399 (2000).
[CrossRef]

Moskovits, M.

M. Moskovits, "Surface-Enhanced Spectroscopy," Rev. Mod. Phys. 57, 783 (1985).
[CrossRef]

Mühlschlegel, P.

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, "Resonant Optical Antennas," Science 308, 1607-1609 (2005).
[CrossRef] [PubMed]

Neacsu, C. C.

C. C. Neacsu, G. A. Steudle, M. B. Raschke, "Plasmonic light scattering from nanoscopic metal tips," Appl. Phys. B 80, 295-300 (2005).
[CrossRef]

C. C. Neacsu, G. A. Reider, and M. B. Raschke, "Second-harmonic generation from nanoscopic metal tips: Symmetry selection rules for single asymmetric nanostructures," Phys. Rev. B 71, 201402 (2005).
[CrossRef]

Nie, S.

S. Nie and S.-R. Emory, "Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering," Science 275, 1102-1106 (1997).
[CrossRef] [PubMed]

Nilius, N.

N. Nilius, N. Ernst, and H.-J. Freund, "Tip influence on plasmon exicitations in single gold particles in an STM," Phys. Rev. B 65, 115421 (2002).
[CrossRef]

Novotny, L.

A. Bouhelier, M. R. Beversluis, and L. Novotny, "Applications of field-enhanced near-field optical microscopy," Ultramicroscopy 100, 413-419 (2004).
[CrossRef] [PubMed]

A. Hartschuh, E. J. Sanchez, X. S. Xie, and L. Novotny, "High-Resolution Near-Field Raman Microscopy of Single-Walled Carbon Nanotubes," Phys. Rev. Lett. 90, 095503 (2003).
[CrossRef] [PubMed]

A. Bouhelier, M. Beversluis, A. Hartschuh, and L. Novotny, "Near-field Second-Harmonic Generation Induced by Local Field Enhancement," Phys. Rev. Lett. 90, 013903 (2003).
[CrossRef] [PubMed]

A. Bouhelier, J. Renger, M.-R. Beversluis, and L. Novotny, "Plasmon-coupled tip-enhanced near-field optical microscopy," J. Microscopy 210, 220-224 (2002).
[CrossRef]

Ordal, M. A.

Osgood, R. M.

N.-C. Panoiu and R. M. Osgood, Jr., "Subwavelength Nonlinear Plasmonic Nanowire," Nano Lett. 4, 2427-2430 (2004).
[CrossRef]

C. J. Chen and R. M. Osgood, "Direct Observation of the Local-Field-Enhanced Surface Photochemical Reactions," Phys. Rev. Lett. 50, 1705-1708 (1983).
[CrossRef]

Panoiu, N.-C.

N.-C. Panoiu and R. M. Osgood, Jr., "Subwavelength Nonlinear Plasmonic Nanowire," Nano Lett. 4, 2427-2430 (2004).
[CrossRef]

Perelman, L. T.

K. Kneipp, Y. Wang, H. Kneipp, L. T. Perelman, I. Itzkan, R. R. Dasari, and M. S. Feld, "Single-Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)," Phys. Rev. Lett. 78, 1667-1670 (1997).
[CrossRef]

Pohl, D. W.

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, "Resonant Optical Antennas," Science 308, 1607-1609 (2005).
[CrossRef] [PubMed]

W. Denk, and D. W. Pohl, "Near-field optics: Microscopy with nanometer-size fields," J. Vac. Sci. Technol. B 9, 510-513 (1991).
[CrossRef]

Porto, J. A.

J. A. Porto, P. Johansson, S. P. Apell, and T. Lopez-Rios, "Resonance shift effects in apertureless scanning near-field optical microscopy," Phys. Rev. B 67, 085409 (2003).
[CrossRef]

L. Aigouy, F. X. Andreani, A. C. Boccara, J. C. Rivoal, J. A. Porto, R. Carminati, J.-J. Greffet, and R. Megy, "Near-field optical spectroscopy using an incoherent light source," Appl. Phys. Lett. 76, 397-399 (2000).
[CrossRef]

Querry, M. R.

Raschke, M. B.

C. C. Neacsu, G. A. Reider, and M. B. Raschke, "Second-harmonic generation from nanoscopic metal tips: Symmetry selection rules for single asymmetric nanostructures," Phys. Rev. B 71, 201402 (2005).
[CrossRef]

C. C. Neacsu, G. A. Steudle, M. B. Raschke, "Plasmonic light scattering from nanoscopic metal tips," Appl. Phys. B 80, 295-300 (2005).
[CrossRef]

Reider, G. A.

C. C. Neacsu, G. A. Reider, and M. B. Raschke, "Second-harmonic generation from nanoscopic metal tips: Symmetry selection rules for single asymmetric nanostructures," Phys. Rev. B 71, 201402 (2005).
[CrossRef]

Renger, J.

A. Bouhelier, J. Renger, M.-R. Beversluis, and L. Novotny, "Plasmon-coupled tip-enhanced near-field optical microscopy," J. Microscopy 210, 220-224 (2002).
[CrossRef]

Richards, D.

A. L. Demming, F. Festy, and D. Richards, "Plasmon resonances on metal tips: Understanding tip-enhanced Raman scattering," J. Chem. Phys. 122, 184716 (2005).
[CrossRef] [PubMed]

Rivoal, J. C.

L. Aigouy, F. X. Andreani, A. C. Boccara, J. C. Rivoal, J. A. Porto, R. Carminati, J.-J. Greffet, and R. Megy, "Near-field optical spectroscopy using an incoherent light source," Appl. Phys. Lett. 76, 397-399 (2000).
[CrossRef]

Sakoda, K.

T. Ito and K. Sakoda, "Photonic bands of metallic systems. II. Features of surface plasmon polaritons," Phys. Rev. B 64, 045117 (2001).
[CrossRef]

Sanchez, E. J.

A. Hartschuh, E. J. Sanchez, X. S. Xie, and L. Novotny, "High-Resolution Near-Field Raman Microscopy of Single-Walled Carbon Nanotubes," Phys. Rev. Lett. 90, 095503 (2003).
[CrossRef] [PubMed]

J. T. Krug, E. J. Sanchez, and S. Xie, "Design of near-field optical probes with optimal field enhancement by finite difference time domain electromagnetic simulation," J. Chem. Phys. 116, 10895-10901 (2002).
[CrossRef]

Schuck, P. J.

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, andW. E.Moerner, "Improving theMismatch between Light and Nanoscale Objects with Gold Bowtie Nanoantennas," Phys. Rev. Lett. 94, 017402 (2005).
[CrossRef] [PubMed]

Steudle, G. A.

C. C. Neacsu, G. A. Steudle, M. B. Raschke, "Plasmonic light scattering from nanoscopic metal tips," Appl. Phys. B 80, 295-300 (2005).
[CrossRef]

Stockman, M. I.

M. I. Stockman, "Nanofocusing of Optical Energy in Tapered Plasmonic Waveguides," Phys. Rev. Lett. 93, 137404 (2004).
[CrossRef] [PubMed]

Sundaramurthy, A.

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, andW. E.Moerner, "Improving theMismatch between Light and Nanoscale Objects with Gold Bowtie Nanoantennas," Phys. Rev. Lett. 94, 017402 (2005).
[CrossRef] [PubMed]

Tiemann, I.

K. Karrai, I. Tiemann, "Interfacial shear force microscopy," Phys. Rev. B 68, 13174 (2000).
[CrossRef]

Van Duyne, R. P.

A. D. McFarland, M. A. Young, J. Dieringer, R. P. Van Duyne, "Wavelength-Scanned Surface Enhanced Raman Excitation Spectroscopy," J. Phys. Chem. B 109, 11279 (2005).
[CrossRef]

C. L. Haynes and R. P. Van Duyne, "Plasmon-Sampled Surface-Enhanced Raman Excitation Spectroscopy," J. Phys. Chem. B 107, 7426-7433 (2003).
[CrossRef]

Wang, Y.

K. Kneipp, Y. Wang, H. Kneipp, L. T. Perelman, I. Itzkan, R. R. Dasari, and M. S. Feld, "Single-Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)," Phys. Rev. Lett. 78, 1667-1670 (1997).
[CrossRef]

West, J. L.

J. L. West and N. J. Halas, "Engineered Nanomaterials for Biophotonics Applications: Improving Sensing, Imaging, and Therapeutics," Ann. Rev. Biomed. Eng. 5, 285-292 (2003).
[CrossRef]

Xie, S.

J. T. Krug, E. J. Sanchez, and S. Xie, "Design of near-field optical probes with optimal field enhancement by finite difference time domain electromagnetic simulation," J. Chem. Phys. 116, 10895-10901 (2002).
[CrossRef]

Xie, X. S.

A. Hartschuh, E. J. Sanchez, X. S. Xie, and L. Novotny, "High-Resolution Near-Field Raman Microscopy of Single-Walled Carbon Nanotubes," Phys. Rev. Lett. 90, 095503 (2003).
[CrossRef] [PubMed]

Xu, C.

Y. Kawata, C. Xu, and W. Denk, "Feasibility of molecular-resolution fluorescence near-field microscopy using multi-photon absorption and field enhancement near a sharp tip," J. Appl. Phys. 85, 1294-1301 (1999).
[CrossRef]

Young, M. A.

A. D. McFarland, M. A. Young, J. Dieringer, R. P. Van Duyne, "Wavelength-Scanned Surface Enhanced Raman Excitation Spectroscopy," J. Phys. Chem. B 109, 11279 (2005).
[CrossRef]

Ann. Rev. Biomed. Eng. (1)

J. L. West and N. J. Halas, "Engineered Nanomaterials for Biophotonics Applications: Improving Sensing, Imaging, and Therapeutics," Ann. Rev. Biomed. Eng. 5, 285-292 (2003).
[CrossRef]

Appl. Opt. (2)

Appl. Phys. B (1)

C. C. Neacsu, G. A. Steudle, M. B. Raschke, "Plasmonic light scattering from nanoscopic metal tips," Appl. Phys. B 80, 295-300 (2005).
[CrossRef]

Appl. Phys. Lett. (1)

L. Aigouy, F. X. Andreani, A. C. Boccara, J. C. Rivoal, J. A. Porto, R. Carminati, J.-J. Greffet, and R. Megy, "Near-field optical spectroscopy using an incoherent light source," Appl. Phys. Lett. 76, 397-399 (2000).
[CrossRef]

J. Appl. Phys. (1)

Y. Kawata, C. Xu, and W. Denk, "Feasibility of molecular-resolution fluorescence near-field microscopy using multi-photon absorption and field enhancement near a sharp tip," J. Appl. Phys. 85, 1294-1301 (1999).
[CrossRef]

J. Chem. Phys. (2)

J. T. Krug, E. J. Sanchez, and S. Xie, "Design of near-field optical probes with optimal field enhancement by finite difference time domain electromagnetic simulation," J. Chem. Phys. 116, 10895-10901 (2002).
[CrossRef]

A. L. Demming, F. Festy, and D. Richards, "Plasmon resonances on metal tips: Understanding tip-enhanced Raman scattering," J. Chem. Phys. 122, 184716 (2005).
[CrossRef] [PubMed]

J. Microscopy (1)

A. Bouhelier, J. Renger, M.-R. Beversluis, and L. Novotny, "Plasmon-coupled tip-enhanced near-field optical microscopy," J. Microscopy 210, 220-224 (2002).
[CrossRef]

J. Phys. Chem. B (3)

A. D. McFarland, M. A. Young, J. Dieringer, R. P. Van Duyne, "Wavelength-Scanned Surface Enhanced Raman Excitation Spectroscopy," J. Phys. Chem. B 109, 11279 (2005).
[CrossRef]

S. Bruzzone, M. Malvaldi, G. Arrighini, and C. Guidotti, "Theoretical Study of Electromagnetic Scattering by Metal Nanoparticles," J. Phys. Chem. B 109, 3807-3812 (2005).
[CrossRef]

C. L. Haynes and R. P. Van Duyne, "Plasmon-Sampled Surface-Enhanced Raman Excitation Spectroscopy," J. Phys. Chem. B 107, 7426-7433 (2003).
[CrossRef]

J. Vac. Sci. Technol. B (1)

W. Denk, and D. W. Pohl, "Near-field optics: Microscopy with nanometer-size fields," J. Vac. Sci. Technol. B 9, 510-513 (1991).
[CrossRef]

Nano Lett. (1)

N.-C. Panoiu and R. M. Osgood, Jr., "Subwavelength Nonlinear Plasmonic Nanowire," Nano Lett. 4, 2427-2430 (2004).
[CrossRef]

Opt. Express (1)

Phil. Trans. R. Soc. Lond. A (1)

F. Keilmann and R. Hillenbrand, "Near-field microscopy by elastic light scattering from a tip," Phil. Trans. R. Soc. Lond. A 362, 787-805 (2004).
[CrossRef]

Phys. Rev. B (6)

C. C. Neacsu, G. A. Reider, and M. B. Raschke, "Second-harmonic generation from nanoscopic metal tips: Symmetry selection rules for single asymmetric nanostructures," Phys. Rev. B 71, 201402 (2005).
[CrossRef]

N. Nilius, N. Ernst, and H.-J. Freund, "Tip influence on plasmon exicitations in single gold particles in an STM," Phys. Rev. B 65, 115421 (2002).
[CrossRef]

J. A. Porto, P. Johansson, S. P. Apell, and T. Lopez-Rios, "Resonance shift effects in apertureless scanning near-field optical microscopy," Phys. Rev. B 67, 085409 (2003).
[CrossRef]

K. Karrai, I. Tiemann, "Interfacial shear force microscopy," Phys. Rev. B 68, 13174 (2000).
[CrossRef]

V. Kuzmiak, A. A. Maradudin, "Photonic band structures of one- and two-dimensional periodic systems with metallic components in the presence of dissipation," Phys. Rev. B 55, 7427-7444 (1997).
[CrossRef]

T. Ito and K. Sakoda, "Photonic bands of metallic systems. II. Features of surface plasmon polaritons," Phys. Rev. B 64, 045117 (2001).
[CrossRef]

Phys. Rev. Lett. (7)

M. I. Stockman, "Nanofocusing of Optical Energy in Tapered Plasmonic Waveguides," Phys. Rev. Lett. 93, 137404 (2004).
[CrossRef] [PubMed]

K. Kneipp, Y. Wang, H. Kneipp, L. T. Perelman, I. Itzkan, R. R. Dasari, and M. S. Feld, "Single-Molecule Detection Using Surface-Enhanced Raman Scattering (SERS)," Phys. Rev. Lett. 78, 1667-1670 (1997).
[CrossRef]

C. J. Chen and R. M. Osgood, "Direct Observation of the Local-Field-Enhanced Surface Photochemical Reactions," Phys. Rev. Lett. 50, 1705-1708 (1983).
[CrossRef]

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, andW. E.Moerner, "Improving theMismatch between Light and Nanoscale Objects with Gold Bowtie Nanoantennas," Phys. Rev. Lett. 94, 017402 (2005).
[CrossRef] [PubMed]

A. Hartschuh, E. J. Sanchez, X. S. Xie, and L. Novotny, "High-Resolution Near-Field Raman Microscopy of Single-Walled Carbon Nanotubes," Phys. Rev. Lett. 90, 095503 (2003).
[CrossRef] [PubMed]

T. Ichimura, N. Hayazawa, M. Hashimoto, Y. Inouye, and S. Kawata, S. "Tip-Enhanced Coherent Anti-Stokes Raman Scattering for Vibrational Nanoimaging," Phys. Rev. Lett. 92, 220801 (2004).
[CrossRef] [PubMed]

A. Bouhelier, M. Beversluis, A. Hartschuh, and L. Novotny, "Near-field Second-Harmonic Generation Induced by Local Field Enhancement," Phys. Rev. Lett. 90, 013903 (2003).
[CrossRef] [PubMed]

Rev. Mod. Phys. (1)

M. Moskovits, "Surface-Enhanced Spectroscopy," Rev. Mod. Phys. 57, 783 (1985).
[CrossRef]

Science (2)

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, "Resonant Optical Antennas," Science 308, 1607-1609 (2005).
[CrossRef] [PubMed]

S. Nie and S.-R. Emory, "Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering," Science 275, 1102-1106 (1997).
[CrossRef] [PubMed]

Ultramicroscopy (1)

A. Bouhelier, M. R. Beversluis, and L. Novotny, "Applications of field-enhanced near-field optical microscopy," Ultramicroscopy 100, 413-419 (2004).
[CrossRef] [PubMed]

Other (6)

A. Downes, D. Salter, and A. Elfick, "Finite Element Simulations of Tip-Enhanced Raman and Fluorescence Spectroscopy," J. Phys. Chem. B (ASAP, 2006), http://pubs.acs.org/cgibin/asap.cgi/jpcbfk/asap/pdf/jp060173w.pdf.
[CrossRef] [PubMed]

J.-P. Fillard, Near Field Optics and Nanoscopy (World Scientific, 1997).

A. Taflove and S. C. Hagness, Computational Electrodynamics: The Finite-Difference Time-Domain Method (Artech House, 2000).

U. Kreibig and M. Vollmer, Optical Properties of Metal Clusters (Springer, 1995).

C. F. Bohrena and D. R. Huffman, Absorption and Scattering of Light by Small Particles (John Wiley, 1998).
[CrossRef]

Similarly, Malachite Green molecules as adsorbate on planar Au surfaces were studied, as described in detail elsewhere: C. C. Neacsu, J. Dreyer, N. Behr, and M. B. Raschke, (Phys. Rev. B, submitted).

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Figures (6)

Fig. 1.
Fig. 1.

Schematic of the tip-sample geometry: the Au tip is modeled as a conical taper terminated by a hemisphere of radius R as its point and elevated a distance d above a Au substrate. The tip length, L, and top diameter, D, remain constant for each simulation (800 nm and 200 nm, respectively). An electromagnetic plane wave of wavelength λ o = 633 nm is incident at an angle θ, and is polarized in the x - z plane.

Fig. 2.
Fig. 2.

The x-z section of the time-averaged spatial profile of the steady-state electric field near the apex of the tip normalized to the amplitude of the incident field. The plot shows a) Ex , b) Ez and c) the total field, respectively. For this simulation, d = 8 nm, R = 10 nm, θ = 30°, and λ o = 633 nm were used. The dashed line and arrow indicate the location of the substrate and tip apex, respectively.

Fig. 3.
Fig. 3.

The field enhancement for Ez for different values of the tip-substrate separation d of (a) d = 8 nm, (b) d = 20 nm and (c) d = ∞ (no substrate). In each case, R = 10 nm, θ = 30°, and λ o = 633 nm. The dashed line and arrow indicate the location of the substrate and tip apex, respectively.

Fig. 4.
Fig. 4.

The enhancement of Ez taken along the x = y = 0 line for various values of d and θ. The substrate location is indicated with a dashed line. As expected, the field strength drops off dramatically upon entering the metal tip or substrate and its maximum strength is located just above the surface of the tip. The field enhancement does not vary strongly with incident angle. Here, R = 10 nm and λ o = 633 nm; θ = 30° for the upper panel and d = 4 nm for the lower panel.

Fig. 5.
Fig. 5.

The spectral response of the tip system for various d (a), R (b), and L (c) values. Various resonant frequencies are present; these resonances can be exploited to make the field enhancement process more efficient. Increasing d can lead to small blue-shifts in the resonant frequencies, while adjusting R only affects the resonant peak amplitude. Note that for ω > ωp (below ~ 200 nm) the actual response deviates due to interband transistions. The dashed line shows the location of λ o = 633 nm (~ 1.96 eV). In (c), R = 10 nm and d = 10 nm.

Fig. 6.
Fig. 6.

Optical field enhancement versus tip-sample distance derived from the tip-enhanced Raman scattering experiment (left). Inset: Corresponding Raman spectra for SWNTs on a Au surface with tip at d ≈ 5 nm (’Tip in’) versus tip-sample distance exceeding the near-field interaction length scale (’Tip out’). Right: Electron micrograph of a typical Au tip used for the experiments (scale bar: 100 nm).

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