Abstract

Sharp geometrical features in crescent-shaped plasmonic nanostructures facilitate electromagnetic hot spots that can be harnessed for sensitive detection of molecules and nanomaterials. For a given geometry of nanocrescent cylinder, the near-field optical resonance and enhancement are constants. It is desirable to tune this resonance and enhancement without altering the geometry of the nanocrescent cylinder. Herein, we numerically show how the near-field resonance and enhancement at the tip of a nanocrescent cylinder can be proximally tuned by incorporating a plasmonic nanostrip in the vicinity. Geometrical parameters, such as the nanocrescent cylinder–nanostrip distance (g) and length (l) of the nanostrip, were varied to tune the near-field optical properties. Our analysis revealed (i) an increment in near-field enhancement at the tip of the nanocrescent cylinder in the presence of a plasmonic nanostrip; (ii) a redshift in the dipolar plasmon mode accompanied by an increase in the near-field enhancement by decreasing g and increasing l, independently; and (iii) variation in the near-field enhancement of plasmonic modes as a function of the excitation angle. Such tunable plasmonic configurations offer capabilities to design wavelength-tuned optical devices without altering the base geometry.

© 2012 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. H. Raether, Surface Plasmons on Smooth and Rough Surfaces and on Gratings (Springer, 1988).
  2. U. Kreibig and M. Vollmer, Optical Properties of Metal Clusters (Springer, 1995).
  3. S. A. Maier, Plasmonics: Fundamentals and Applications (Springer, 2007).
  4. L. Novotny and B. Hecht, Principles of Nano-Optics (Cambridge University, 2006).
  5. H. A. Atwater, “The promise of plasmonics,” Sci. Am. 296, 56–62 (2007).
    [CrossRef]
  6. W. L. Barnes, A. Dereux, and T. W. Ebbesen, “Surface plasmon subwavelength optics,” Nature 424, 824–830 (2003).
    [CrossRef]
  7. M. Pelton, J. Aizpurua, and G. Bryant, “Metal–nanoparticle plasmonics,” Laser Photon. Rev. 2, 136–159 (2008).
    [CrossRef]
  8. M. Moskovits, “Surface-enhanced spectroscopy,” Rev. Mod. Phys. 57, 783–826 (1985).
    [CrossRef]
  9. E. C. Le Ru and P. G. Etchegoin, Principles of Surface-Enhanced Raman Spectroscopy and Related Plasmonic Effects (Elsevier, 2009).
  10. G. Moula and R. F. Aroca, “Plasmon-enhanced resonance Raman scattering and fluorescence in Langmuir–Blodgett monolayers,” Anal. Chem. 83, 284–288 (2011).
    [CrossRef]
  11. S. Kawata and V. M. Shalaev, eds., Tip Enhancement (Elsevier, 2007).
  12. P. Bharadwaj, B. Deutsch, and L. Novotny, “Optical antennas,” Adv. Opt. Photon. 1, 438–483 (2009).
    [CrossRef]
  13. N. J. Halas, S. Lal, W. S. Chang, S. Link, and P. Nordlander, “Plasmons in strongly coupled metallic nanostructures,” Chem. Rev. 111, 3913–3961 (2011).
    [CrossRef]
  14. J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7, 442–453 (2008).
    [CrossRef]
  15. S. Zhang, H. Liu, and G. Mu, “Electromagnetic enhancement by a periodic array of nanogrooves in a metallic substrate,” J. Opt. Soc. Am. A 28, 879–886 (2011).
    [CrossRef]
  16. H. Xu, H. Li, Z. Liu, S. Xie, X. Zhou, X. Peng, and X. Xu, “Effects of symmetry breaking on plasmon resonance in a noncoaxial nanotube and nanotube dimer,” J. Opt. Soc. Am. A 28, 1662–1667 (2011).
    [CrossRef]
  17. G. L. Liu, Y. Lu, J. Kim, J. C. Doll, and L. P. Lee, “Magnetic nanocrescents as controllable surface-enhanced Raman scattering nanoprobes for biomolecular imaging,” Adv. Mater. 17, 2683–2688 (2005).
    [CrossRef]
  18. J. S. Shumaker-Parry, H. Rochholz, and M. Kreiter, “Fabrication of crescent-shaped optical antennas,” Adv. Mater. 17, 2131–2134 (2005).
    [CrossRef]
  19. L. Yu, G. L. Liu, J. Kim, Y. X. Mejia, and L. P. Lee, “Nanophotonic crescent moon structures with sharp edge for ultrasensitive biomolecular detection by local electromagnetic field enhancement effect,” Nano Lett. 5, 119–124 (2005).
    [CrossRef]
  20. R. Bukasov and J. S. Shumaker-Parry, “Highly tunable infrared extinction properties of gold nanocrescents,” Nano Lett. 7, 1113–1118 (2007).
    [CrossRef]
  21. H. Rochholz, N. Bocchio, and M. Kreiter, “Tuning resonances on crescent-shaped noble-metal nanoparticles,” New J. Phys. 9, 53 (2007).
    [CrossRef]
  22. Y. Zhang, T. Q. Jia, D. H. Feng, and Z. Z. Xu, “Quadrupole plasmon resonance mode in nanocrescent/nanodisk structure: local field enhancement and tunability in the visible light region,” Appl. Phys. Lett. 98, 163110 (2011).
    [CrossRef]
  23. A. Aubry, D. Y. Lei, A. I. Fernandez-Dominguez, Y. Sonnefraud, S. A. Maier, and J. B. Pendry, “Plasmonic light-harvesting devices over the whole visible spectrum,” Nano Lett. 10, 2574–2579 (2010).
    [CrossRef]
  24. A. Aubry, D. Y. Lei, S. A. Maier, and J. B. Pendry, “Broadband plasmonic device concentrating the energy at the nanoscale: the crescent-shaped cylinder,” Phys. Rev. B 82, 125430 (2010).
    [CrossRef]
  25. B. M. Ross and L. P. Lee, “Plasmon tuning and local field enhancement maximization of the nanocrescent,” Nanotechnology 19, 275201 (2008).
    [CrossRef]
  26. L. Feng, D. Van Orden, M. Abashin, Q. J. Wang, Y. F. Chen, V. Lomakin, and Y. Fainman, “Nanoscale optical field localization by resonantly focused plasmons,” Opt. Express 17, 4824–4832 (2009).
    [CrossRef]
  27. K. Li, L. Clime, B. Cui, and T. Veres, “Surface enhanced Raman scattering on long-range ordered noble-metal nanocrescent arrays,” Nanotechnology 19, 145305 (2008).
    [CrossRef]
  28. L. Y. Wu, B. M. Ross, and L. P. Lee, “Optical properties of the crescent-shaped nanohole antenna,” Nano Lett. 9, 1956–1961 (2009).
    [CrossRef]
  29. R. Bukasov, T. A. Ali, P. Nordlander, and J. S. Shumaker-Parry, “Probing the plasmonic near-field of gold nanocrescent antennas,” ACS Nano 4, 6639–6650 (2010).
    [CrossRef]
  30. A. Unger, U. Rietzler, R. Berger, and M. Kreiter, “Sensitivity of crescent-shaped metal nanoparticles to attachment of dielectric colloids,” Nano Lett. 9, 2311–2315 (2009).
    [CrossRef]
  31. P. B. Johnson and R. W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370–4379 (1972).
    [CrossRef]
  32. B. Pettinger, K. F. Domke, D. Zhang, G. Picardi, and R. Schuster, “Tip-enhanced Raman scattering: influence of the tip-surface geometry on optical resonance and enhancement,” Surf. Sci. 603, 1335–1341 (2009).
    [CrossRef]
  33. R. Berndt, J. K. Gimzewski, and P. Johansson, “Electromagnetic interactions of metallic objects in nanometer proximity,” Phys. Rev. Lett. 71, 3493–3496 (1993).
    [CrossRef]
  34. B. Pettinger, K. F. Domke, D. Zhang, R. Schuster, and G. Ertl, “Direct monitoring of plasmon resonances in a tip-surface gap of varying width,” Phys. Rev. B 76, 113409 (2007).
    [CrossRef]
  35. M.-J. Sung, Y.-F. Ma, Y.-F. Chau, and D.-W. Huang, “Surface plasmon resonance in a hexagonal nanostructure formed by seven core shell nanocylinders,” Appl. Opt. 49, 920–926 (2010).
    [CrossRef]
  36. A. G. Curto, G. Volpe, T. H. Taminiau, M. P. Kreuzer, R. Quidant, and N. F. Van Hulst, “Unidirectional emission of a quantum dot coupled to a nanoantenna,” Science 329, 930–933 (2010).
    [CrossRef]
  37. G. V. Pavan Kumar, “Near-field optical properties of silver nanocylinders arranged in a Pascal triangle,” Appl. Opt. 49, 6872–6877 (2010).
    [CrossRef]
  38. A. Alu and N. Engheta, “Input impedance, nanocircuit loading, and radiation tuning of optical nanoantennas,” Phys. Rev. Lett. 101, 043901 (2008).
    [CrossRef]
  39. A. Alu and N. Engheta, “Tuning the scattering response of optical nanoantennas with nanocircuit loads,” Nat. Photon. 2, 307–310 (2008).
    [CrossRef]

2011 (5)

G. Moula and R. F. Aroca, “Plasmon-enhanced resonance Raman scattering and fluorescence in Langmuir–Blodgett monolayers,” Anal. Chem. 83, 284–288 (2011).
[CrossRef]

N. J. Halas, S. Lal, W. S. Chang, S. Link, and P. Nordlander, “Plasmons in strongly coupled metallic nanostructures,” Chem. Rev. 111, 3913–3961 (2011).
[CrossRef]

Y. Zhang, T. Q. Jia, D. H. Feng, and Z. Z. Xu, “Quadrupole plasmon resonance mode in nanocrescent/nanodisk structure: local field enhancement and tunability in the visible light region,” Appl. Phys. Lett. 98, 163110 (2011).
[CrossRef]

S. Zhang, H. Liu, and G. Mu, “Electromagnetic enhancement by a periodic array of nanogrooves in a metallic substrate,” J. Opt. Soc. Am. A 28, 879–886 (2011).
[CrossRef]

H. Xu, H. Li, Z. Liu, S. Xie, X. Zhou, X. Peng, and X. Xu, “Effects of symmetry breaking on plasmon resonance in a noncoaxial nanotube and nanotube dimer,” J. Opt. Soc. Am. A 28, 1662–1667 (2011).
[CrossRef]

2010 (6)

M.-J. Sung, Y.-F. Ma, Y.-F. Chau, and D.-W. Huang, “Surface plasmon resonance in a hexagonal nanostructure formed by seven core shell nanocylinders,” Appl. Opt. 49, 920–926 (2010).
[CrossRef]

G. V. Pavan Kumar, “Near-field optical properties of silver nanocylinders arranged in a Pascal triangle,” Appl. Opt. 49, 6872–6877 (2010).
[CrossRef]

A. G. Curto, G. Volpe, T. H. Taminiau, M. P. Kreuzer, R. Quidant, and N. F. Van Hulst, “Unidirectional emission of a quantum dot coupled to a nanoantenna,” Science 329, 930–933 (2010).
[CrossRef]

A. Aubry, D. Y. Lei, A. I. Fernandez-Dominguez, Y. Sonnefraud, S. A. Maier, and J. B. Pendry, “Plasmonic light-harvesting devices over the whole visible spectrum,” Nano Lett. 10, 2574–2579 (2010).
[CrossRef]

A. Aubry, D. Y. Lei, S. A. Maier, and J. B. Pendry, “Broadband plasmonic device concentrating the energy at the nanoscale: the crescent-shaped cylinder,” Phys. Rev. B 82, 125430 (2010).
[CrossRef]

R. Bukasov, T. A. Ali, P. Nordlander, and J. S. Shumaker-Parry, “Probing the plasmonic near-field of gold nanocrescent antennas,” ACS Nano 4, 6639–6650 (2010).
[CrossRef]

2009 (5)

A. Unger, U. Rietzler, R. Berger, and M. Kreiter, “Sensitivity of crescent-shaped metal nanoparticles to attachment of dielectric colloids,” Nano Lett. 9, 2311–2315 (2009).
[CrossRef]

L. Feng, D. Van Orden, M. Abashin, Q. J. Wang, Y. F. Chen, V. Lomakin, and Y. Fainman, “Nanoscale optical field localization by resonantly focused plasmons,” Opt. Express 17, 4824–4832 (2009).
[CrossRef]

P. Bharadwaj, B. Deutsch, and L. Novotny, “Optical antennas,” Adv. Opt. Photon. 1, 438–483 (2009).
[CrossRef]

B. Pettinger, K. F. Domke, D. Zhang, G. Picardi, and R. Schuster, “Tip-enhanced Raman scattering: influence of the tip-surface geometry on optical resonance and enhancement,” Surf. Sci. 603, 1335–1341 (2009).
[CrossRef]

L. Y. Wu, B. M. Ross, and L. P. Lee, “Optical properties of the crescent-shaped nanohole antenna,” Nano Lett. 9, 1956–1961 (2009).
[CrossRef]

2008 (6)

A. Alu and N. Engheta, “Input impedance, nanocircuit loading, and radiation tuning of optical nanoantennas,” Phys. Rev. Lett. 101, 043901 (2008).
[CrossRef]

A. Alu and N. Engheta, “Tuning the scattering response of optical nanoantennas with nanocircuit loads,” Nat. Photon. 2, 307–310 (2008).
[CrossRef]

B. M. Ross and L. P. Lee, “Plasmon tuning and local field enhancement maximization of the nanocrescent,” Nanotechnology 19, 275201 (2008).
[CrossRef]

K. Li, L. Clime, B. Cui, and T. Veres, “Surface enhanced Raman scattering on long-range ordered noble-metal nanocrescent arrays,” Nanotechnology 19, 145305 (2008).
[CrossRef]

J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7, 442–453 (2008).
[CrossRef]

M. Pelton, J. Aizpurua, and G. Bryant, “Metal–nanoparticle plasmonics,” Laser Photon. Rev. 2, 136–159 (2008).
[CrossRef]

2007 (4)

H. A. Atwater, “The promise of plasmonics,” Sci. Am. 296, 56–62 (2007).
[CrossRef]

R. Bukasov and J. S. Shumaker-Parry, “Highly tunable infrared extinction properties of gold nanocrescents,” Nano Lett. 7, 1113–1118 (2007).
[CrossRef]

H. Rochholz, N. Bocchio, and M. Kreiter, “Tuning resonances on crescent-shaped noble-metal nanoparticles,” New J. Phys. 9, 53 (2007).
[CrossRef]

B. Pettinger, K. F. Domke, D. Zhang, R. Schuster, and G. Ertl, “Direct monitoring of plasmon resonances in a tip-surface gap of varying width,” Phys. Rev. B 76, 113409 (2007).
[CrossRef]

2005 (3)

G. L. Liu, Y. Lu, J. Kim, J. C. Doll, and L. P. Lee, “Magnetic nanocrescents as controllable surface-enhanced Raman scattering nanoprobes for biomolecular imaging,” Adv. Mater. 17, 2683–2688 (2005).
[CrossRef]

J. S. Shumaker-Parry, H. Rochholz, and M. Kreiter, “Fabrication of crescent-shaped optical antennas,” Adv. Mater. 17, 2131–2134 (2005).
[CrossRef]

L. Yu, G. L. Liu, J. Kim, Y. X. Mejia, and L. P. Lee, “Nanophotonic crescent moon structures with sharp edge for ultrasensitive biomolecular detection by local electromagnetic field enhancement effect,” Nano Lett. 5, 119–124 (2005).
[CrossRef]

2003 (1)

W. L. Barnes, A. Dereux, and T. W. Ebbesen, “Surface plasmon subwavelength optics,” Nature 424, 824–830 (2003).
[CrossRef]

1993 (1)

R. Berndt, J. K. Gimzewski, and P. Johansson, “Electromagnetic interactions of metallic objects in nanometer proximity,” Phys. Rev. Lett. 71, 3493–3496 (1993).
[CrossRef]

1985 (1)

M. Moskovits, “Surface-enhanced spectroscopy,” Rev. Mod. Phys. 57, 783–826 (1985).
[CrossRef]

1972 (1)

P. B. Johnson and R. W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370–4379 (1972).
[CrossRef]

Abashin, M.

Aizpurua, J.

M. Pelton, J. Aizpurua, and G. Bryant, “Metal–nanoparticle plasmonics,” Laser Photon. Rev. 2, 136–159 (2008).
[CrossRef]

Ali, T. A.

R. Bukasov, T. A. Ali, P. Nordlander, and J. S. Shumaker-Parry, “Probing the plasmonic near-field of gold nanocrescent antennas,” ACS Nano 4, 6639–6650 (2010).
[CrossRef]

Alu, A.

A. Alu and N. Engheta, “Tuning the scattering response of optical nanoantennas with nanocircuit loads,” Nat. Photon. 2, 307–310 (2008).
[CrossRef]

A. Alu and N. Engheta, “Input impedance, nanocircuit loading, and radiation tuning of optical nanoantennas,” Phys. Rev. Lett. 101, 043901 (2008).
[CrossRef]

Anker, J. N.

J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7, 442–453 (2008).
[CrossRef]

Aroca, R. F.

G. Moula and R. F. Aroca, “Plasmon-enhanced resonance Raman scattering and fluorescence in Langmuir–Blodgett monolayers,” Anal. Chem. 83, 284–288 (2011).
[CrossRef]

Atwater, H. A.

H. A. Atwater, “The promise of plasmonics,” Sci. Am. 296, 56–62 (2007).
[CrossRef]

Aubry, A.

A. Aubry, D. Y. Lei, S. A. Maier, and J. B. Pendry, “Broadband plasmonic device concentrating the energy at the nanoscale: the crescent-shaped cylinder,” Phys. Rev. B 82, 125430 (2010).
[CrossRef]

A. Aubry, D. Y. Lei, A. I. Fernandez-Dominguez, Y. Sonnefraud, S. A. Maier, and J. B. Pendry, “Plasmonic light-harvesting devices over the whole visible spectrum,” Nano Lett. 10, 2574–2579 (2010).
[CrossRef]

Barnes, W. L.

W. L. Barnes, A. Dereux, and T. W. Ebbesen, “Surface plasmon subwavelength optics,” Nature 424, 824–830 (2003).
[CrossRef]

Berger, R.

A. Unger, U. Rietzler, R. Berger, and M. Kreiter, “Sensitivity of crescent-shaped metal nanoparticles to attachment of dielectric colloids,” Nano Lett. 9, 2311–2315 (2009).
[CrossRef]

Berndt, R.

R. Berndt, J. K. Gimzewski, and P. Johansson, “Electromagnetic interactions of metallic objects in nanometer proximity,” Phys. Rev. Lett. 71, 3493–3496 (1993).
[CrossRef]

Bharadwaj, P.

Bocchio, N.

H. Rochholz, N. Bocchio, and M. Kreiter, “Tuning resonances on crescent-shaped noble-metal nanoparticles,” New J. Phys. 9, 53 (2007).
[CrossRef]

Bryant, G.

M. Pelton, J. Aizpurua, and G. Bryant, “Metal–nanoparticle plasmonics,” Laser Photon. Rev. 2, 136–159 (2008).
[CrossRef]

Bukasov, R.

R. Bukasov, T. A. Ali, P. Nordlander, and J. S. Shumaker-Parry, “Probing the plasmonic near-field of gold nanocrescent antennas,” ACS Nano 4, 6639–6650 (2010).
[CrossRef]

R. Bukasov and J. S. Shumaker-Parry, “Highly tunable infrared extinction properties of gold nanocrescents,” Nano Lett. 7, 1113–1118 (2007).
[CrossRef]

Chang, W. S.

N. J. Halas, S. Lal, W. S. Chang, S. Link, and P. Nordlander, “Plasmons in strongly coupled metallic nanostructures,” Chem. Rev. 111, 3913–3961 (2011).
[CrossRef]

Chau, Y.-F.

Chen, Y. F.

Christy, R. W.

P. B. Johnson and R. W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370–4379 (1972).
[CrossRef]

Clime, L.

K. Li, L. Clime, B. Cui, and T. Veres, “Surface enhanced Raman scattering on long-range ordered noble-metal nanocrescent arrays,” Nanotechnology 19, 145305 (2008).
[CrossRef]

Cui, B.

K. Li, L. Clime, B. Cui, and T. Veres, “Surface enhanced Raman scattering on long-range ordered noble-metal nanocrescent arrays,” Nanotechnology 19, 145305 (2008).
[CrossRef]

Curto, A. G.

A. G. Curto, G. Volpe, T. H. Taminiau, M. P. Kreuzer, R. Quidant, and N. F. Van Hulst, “Unidirectional emission of a quantum dot coupled to a nanoantenna,” Science 329, 930–933 (2010).
[CrossRef]

Dereux, A.

W. L. Barnes, A. Dereux, and T. W. Ebbesen, “Surface plasmon subwavelength optics,” Nature 424, 824–830 (2003).
[CrossRef]

Deutsch, B.

Doll, J. C.

G. L. Liu, Y. Lu, J. Kim, J. C. Doll, and L. P. Lee, “Magnetic nanocrescents as controllable surface-enhanced Raman scattering nanoprobes for biomolecular imaging,” Adv. Mater. 17, 2683–2688 (2005).
[CrossRef]

Domke, K. F.

B. Pettinger, K. F. Domke, D. Zhang, G. Picardi, and R. Schuster, “Tip-enhanced Raman scattering: influence of the tip-surface geometry on optical resonance and enhancement,” Surf. Sci. 603, 1335–1341 (2009).
[CrossRef]

B. Pettinger, K. F. Domke, D. Zhang, R. Schuster, and G. Ertl, “Direct monitoring of plasmon resonances in a tip-surface gap of varying width,” Phys. Rev. B 76, 113409 (2007).
[CrossRef]

Ebbesen, T. W.

W. L. Barnes, A. Dereux, and T. W. Ebbesen, “Surface plasmon subwavelength optics,” Nature 424, 824–830 (2003).
[CrossRef]

Engheta, N.

A. Alu and N. Engheta, “Input impedance, nanocircuit loading, and radiation tuning of optical nanoantennas,” Phys. Rev. Lett. 101, 043901 (2008).
[CrossRef]

A. Alu and N. Engheta, “Tuning the scattering response of optical nanoantennas with nanocircuit loads,” Nat. Photon. 2, 307–310 (2008).
[CrossRef]

Ertl, G.

B. Pettinger, K. F. Domke, D. Zhang, R. Schuster, and G. Ertl, “Direct monitoring of plasmon resonances in a tip-surface gap of varying width,” Phys. Rev. B 76, 113409 (2007).
[CrossRef]

Etchegoin, P. G.

E. C. Le Ru and P. G. Etchegoin, Principles of Surface-Enhanced Raman Spectroscopy and Related Plasmonic Effects (Elsevier, 2009).

Fainman, Y.

Feng, D. H.

Y. Zhang, T. Q. Jia, D. H. Feng, and Z. Z. Xu, “Quadrupole plasmon resonance mode in nanocrescent/nanodisk structure: local field enhancement and tunability in the visible light region,” Appl. Phys. Lett. 98, 163110 (2011).
[CrossRef]

Feng, L.

Fernandez-Dominguez, A. I.

A. Aubry, D. Y. Lei, A. I. Fernandez-Dominguez, Y. Sonnefraud, S. A. Maier, and J. B. Pendry, “Plasmonic light-harvesting devices over the whole visible spectrum,” Nano Lett. 10, 2574–2579 (2010).
[CrossRef]

Gimzewski, J. K.

R. Berndt, J. K. Gimzewski, and P. Johansson, “Electromagnetic interactions of metallic objects in nanometer proximity,” Phys. Rev. Lett. 71, 3493–3496 (1993).
[CrossRef]

Halas, N. J.

N. J. Halas, S. Lal, W. S. Chang, S. Link, and P. Nordlander, “Plasmons in strongly coupled metallic nanostructures,” Chem. Rev. 111, 3913–3961 (2011).
[CrossRef]

Hall, W. P.

J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7, 442–453 (2008).
[CrossRef]

Hecht, B.

L. Novotny and B. Hecht, Principles of Nano-Optics (Cambridge University, 2006).

Huang, D.-W.

Jia, T. Q.

Y. Zhang, T. Q. Jia, D. H. Feng, and Z. Z. Xu, “Quadrupole plasmon resonance mode in nanocrescent/nanodisk structure: local field enhancement and tunability in the visible light region,” Appl. Phys. Lett. 98, 163110 (2011).
[CrossRef]

Johansson, P.

R. Berndt, J. K. Gimzewski, and P. Johansson, “Electromagnetic interactions of metallic objects in nanometer proximity,” Phys. Rev. Lett. 71, 3493–3496 (1993).
[CrossRef]

Johnson, P. B.

P. B. Johnson and R. W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370–4379 (1972).
[CrossRef]

Kim, J.

G. L. Liu, Y. Lu, J. Kim, J. C. Doll, and L. P. Lee, “Magnetic nanocrescents as controllable surface-enhanced Raman scattering nanoprobes for biomolecular imaging,” Adv. Mater. 17, 2683–2688 (2005).
[CrossRef]

L. Yu, G. L. Liu, J. Kim, Y. X. Mejia, and L. P. Lee, “Nanophotonic crescent moon structures with sharp edge for ultrasensitive biomolecular detection by local electromagnetic field enhancement effect,” Nano Lett. 5, 119–124 (2005).
[CrossRef]

Kreibig, U.

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

Kreiter, M.

A. Unger, U. Rietzler, R. Berger, and M. Kreiter, “Sensitivity of crescent-shaped metal nanoparticles to attachment of dielectric colloids,” Nano Lett. 9, 2311–2315 (2009).
[CrossRef]

H. Rochholz, N. Bocchio, and M. Kreiter, “Tuning resonances on crescent-shaped noble-metal nanoparticles,” New J. Phys. 9, 53 (2007).
[CrossRef]

J. S. Shumaker-Parry, H. Rochholz, and M. Kreiter, “Fabrication of crescent-shaped optical antennas,” Adv. Mater. 17, 2131–2134 (2005).
[CrossRef]

Kreuzer, M. P.

A. G. Curto, G. Volpe, T. H. Taminiau, M. P. Kreuzer, R. Quidant, and N. F. Van Hulst, “Unidirectional emission of a quantum dot coupled to a nanoantenna,” Science 329, 930–933 (2010).
[CrossRef]

Lal, S.

N. J. Halas, S. Lal, W. S. Chang, S. Link, and P. Nordlander, “Plasmons in strongly coupled metallic nanostructures,” Chem. Rev. 111, 3913–3961 (2011).
[CrossRef]

Le Ru, E. C.

E. C. Le Ru and P. G. Etchegoin, Principles of Surface-Enhanced Raman Spectroscopy and Related Plasmonic Effects (Elsevier, 2009).

Lee, L. P.

L. Y. Wu, B. M. Ross, and L. P. Lee, “Optical properties of the crescent-shaped nanohole antenna,” Nano Lett. 9, 1956–1961 (2009).
[CrossRef]

B. M. Ross and L. P. Lee, “Plasmon tuning and local field enhancement maximization of the nanocrescent,” Nanotechnology 19, 275201 (2008).
[CrossRef]

L. Yu, G. L. Liu, J. Kim, Y. X. Mejia, and L. P. Lee, “Nanophotonic crescent moon structures with sharp edge for ultrasensitive biomolecular detection by local electromagnetic field enhancement effect,” Nano Lett. 5, 119–124 (2005).
[CrossRef]

G. L. Liu, Y. Lu, J. Kim, J. C. Doll, and L. P. Lee, “Magnetic nanocrescents as controllable surface-enhanced Raman scattering nanoprobes for biomolecular imaging,” Adv. Mater. 17, 2683–2688 (2005).
[CrossRef]

Lei, D. Y.

A. Aubry, D. Y. Lei, S. A. Maier, and J. B. Pendry, “Broadband plasmonic device concentrating the energy at the nanoscale: the crescent-shaped cylinder,” Phys. Rev. B 82, 125430 (2010).
[CrossRef]

A. Aubry, D. Y. Lei, A. I. Fernandez-Dominguez, Y. Sonnefraud, S. A. Maier, and J. B. Pendry, “Plasmonic light-harvesting devices over the whole visible spectrum,” Nano Lett. 10, 2574–2579 (2010).
[CrossRef]

Li, H.

Li, K.

K. Li, L. Clime, B. Cui, and T. Veres, “Surface enhanced Raman scattering on long-range ordered noble-metal nanocrescent arrays,” Nanotechnology 19, 145305 (2008).
[CrossRef]

Link, S.

N. J. Halas, S. Lal, W. S. Chang, S. Link, and P. Nordlander, “Plasmons in strongly coupled metallic nanostructures,” Chem. Rev. 111, 3913–3961 (2011).
[CrossRef]

Liu, G. L.

G. L. Liu, Y. Lu, J. Kim, J. C. Doll, and L. P. Lee, “Magnetic nanocrescents as controllable surface-enhanced Raman scattering nanoprobes for biomolecular imaging,” Adv. Mater. 17, 2683–2688 (2005).
[CrossRef]

L. Yu, G. L. Liu, J. Kim, Y. X. Mejia, and L. P. Lee, “Nanophotonic crescent moon structures with sharp edge for ultrasensitive biomolecular detection by local electromagnetic field enhancement effect,” Nano Lett. 5, 119–124 (2005).
[CrossRef]

Liu, H.

Liu, Z.

Lomakin, V.

Lu, Y.

G. L. Liu, Y. Lu, J. Kim, J. C. Doll, and L. P. Lee, “Magnetic nanocrescents as controllable surface-enhanced Raman scattering nanoprobes for biomolecular imaging,” Adv. Mater. 17, 2683–2688 (2005).
[CrossRef]

Lyandres, O.

J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7, 442–453 (2008).
[CrossRef]

Ma, Y.-F.

Maier, S. A.

A. Aubry, D. Y. Lei, S. A. Maier, and J. B. Pendry, “Broadband plasmonic device concentrating the energy at the nanoscale: the crescent-shaped cylinder,” Phys. Rev. B 82, 125430 (2010).
[CrossRef]

A. Aubry, D. Y. Lei, A. I. Fernandez-Dominguez, Y. Sonnefraud, S. A. Maier, and J. B. Pendry, “Plasmonic light-harvesting devices over the whole visible spectrum,” Nano Lett. 10, 2574–2579 (2010).
[CrossRef]

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

Mejia, Y. X.

L. Yu, G. L. Liu, J. Kim, Y. X. Mejia, and L. P. Lee, “Nanophotonic crescent moon structures with sharp edge for ultrasensitive biomolecular detection by local electromagnetic field enhancement effect,” Nano Lett. 5, 119–124 (2005).
[CrossRef]

Moskovits, M.

M. Moskovits, “Surface-enhanced spectroscopy,” Rev. Mod. Phys. 57, 783–826 (1985).
[CrossRef]

Moula, G.

G. Moula and R. F. Aroca, “Plasmon-enhanced resonance Raman scattering and fluorescence in Langmuir–Blodgett monolayers,” Anal. Chem. 83, 284–288 (2011).
[CrossRef]

Mu, G.

Nordlander, P.

N. J. Halas, S. Lal, W. S. Chang, S. Link, and P. Nordlander, “Plasmons in strongly coupled metallic nanostructures,” Chem. Rev. 111, 3913–3961 (2011).
[CrossRef]

R. Bukasov, T. A. Ali, P. Nordlander, and J. S. Shumaker-Parry, “Probing the plasmonic near-field of gold nanocrescent antennas,” ACS Nano 4, 6639–6650 (2010).
[CrossRef]

Novotny, L.

P. Bharadwaj, B. Deutsch, and L. Novotny, “Optical antennas,” Adv. Opt. Photon. 1, 438–483 (2009).
[CrossRef]

L. Novotny and B. Hecht, Principles of Nano-Optics (Cambridge University, 2006).

Pavan Kumar, G. V.

Pelton, M.

M. Pelton, J. Aizpurua, and G. Bryant, “Metal–nanoparticle plasmonics,” Laser Photon. Rev. 2, 136–159 (2008).
[CrossRef]

Pendry, J. B.

A. Aubry, D. Y. Lei, S. A. Maier, and J. B. Pendry, “Broadband plasmonic device concentrating the energy at the nanoscale: the crescent-shaped cylinder,” Phys. Rev. B 82, 125430 (2010).
[CrossRef]

A. Aubry, D. Y. Lei, A. I. Fernandez-Dominguez, Y. Sonnefraud, S. A. Maier, and J. B. Pendry, “Plasmonic light-harvesting devices over the whole visible spectrum,” Nano Lett. 10, 2574–2579 (2010).
[CrossRef]

Peng, X.

Pettinger, B.

B. Pettinger, K. F. Domke, D. Zhang, G. Picardi, and R. Schuster, “Tip-enhanced Raman scattering: influence of the tip-surface geometry on optical resonance and enhancement,” Surf. Sci. 603, 1335–1341 (2009).
[CrossRef]

B. Pettinger, K. F. Domke, D. Zhang, R. Schuster, and G. Ertl, “Direct monitoring of plasmon resonances in a tip-surface gap of varying width,” Phys. Rev. B 76, 113409 (2007).
[CrossRef]

Picardi, G.

B. Pettinger, K. F. Domke, D. Zhang, G. Picardi, and R. Schuster, “Tip-enhanced Raman scattering: influence of the tip-surface geometry on optical resonance and enhancement,” Surf. Sci. 603, 1335–1341 (2009).
[CrossRef]

Quidant, R.

A. G. Curto, G. Volpe, T. H. Taminiau, M. P. Kreuzer, R. Quidant, and N. F. Van Hulst, “Unidirectional emission of a quantum dot coupled to a nanoantenna,” Science 329, 930–933 (2010).
[CrossRef]

Raether, H.

H. Raether, Surface Plasmons on Smooth and Rough Surfaces and on Gratings (Springer, 1988).

Rietzler, U.

A. Unger, U. Rietzler, R. Berger, and M. Kreiter, “Sensitivity of crescent-shaped metal nanoparticles to attachment of dielectric colloids,” Nano Lett. 9, 2311–2315 (2009).
[CrossRef]

Rochholz, H.

H. Rochholz, N. Bocchio, and M. Kreiter, “Tuning resonances on crescent-shaped noble-metal nanoparticles,” New J. Phys. 9, 53 (2007).
[CrossRef]

J. S. Shumaker-Parry, H. Rochholz, and M. Kreiter, “Fabrication of crescent-shaped optical antennas,” Adv. Mater. 17, 2131–2134 (2005).
[CrossRef]

Ross, B. M.

L. Y. Wu, B. M. Ross, and L. P. Lee, “Optical properties of the crescent-shaped nanohole antenna,” Nano Lett. 9, 1956–1961 (2009).
[CrossRef]

B. M. Ross and L. P. Lee, “Plasmon tuning and local field enhancement maximization of the nanocrescent,” Nanotechnology 19, 275201 (2008).
[CrossRef]

Schuster, R.

B. Pettinger, K. F. Domke, D. Zhang, G. Picardi, and R. Schuster, “Tip-enhanced Raman scattering: influence of the tip-surface geometry on optical resonance and enhancement,” Surf. Sci. 603, 1335–1341 (2009).
[CrossRef]

B. Pettinger, K. F. Domke, D. Zhang, R. Schuster, and G. Ertl, “Direct monitoring of plasmon resonances in a tip-surface gap of varying width,” Phys. Rev. B 76, 113409 (2007).
[CrossRef]

Shah, N. C.

J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7, 442–453 (2008).
[CrossRef]

Shumaker-Parry, J. S.

R. Bukasov, T. A. Ali, P. Nordlander, and J. S. Shumaker-Parry, “Probing the plasmonic near-field of gold nanocrescent antennas,” ACS Nano 4, 6639–6650 (2010).
[CrossRef]

R. Bukasov and J. S. Shumaker-Parry, “Highly tunable infrared extinction properties of gold nanocrescents,” Nano Lett. 7, 1113–1118 (2007).
[CrossRef]

J. S. Shumaker-Parry, H. Rochholz, and M. Kreiter, “Fabrication of crescent-shaped optical antennas,” Adv. Mater. 17, 2131–2134 (2005).
[CrossRef]

Sonnefraud, Y.

A. Aubry, D. Y. Lei, A. I. Fernandez-Dominguez, Y. Sonnefraud, S. A. Maier, and J. B. Pendry, “Plasmonic light-harvesting devices over the whole visible spectrum,” Nano Lett. 10, 2574–2579 (2010).
[CrossRef]

Sung, M.-J.

Taminiau, T. H.

A. G. Curto, G. Volpe, T. H. Taminiau, M. P. Kreuzer, R. Quidant, and N. F. Van Hulst, “Unidirectional emission of a quantum dot coupled to a nanoantenna,” Science 329, 930–933 (2010).
[CrossRef]

Unger, A.

A. Unger, U. Rietzler, R. Berger, and M. Kreiter, “Sensitivity of crescent-shaped metal nanoparticles to attachment of dielectric colloids,” Nano Lett. 9, 2311–2315 (2009).
[CrossRef]

Van Duyne, R. P.

J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7, 442–453 (2008).
[CrossRef]

Van Hulst, N. F.

A. G. Curto, G. Volpe, T. H. Taminiau, M. P. Kreuzer, R. Quidant, and N. F. Van Hulst, “Unidirectional emission of a quantum dot coupled to a nanoantenna,” Science 329, 930–933 (2010).
[CrossRef]

Van Orden, D.

Veres, T.

K. Li, L. Clime, B. Cui, and T. Veres, “Surface enhanced Raman scattering on long-range ordered noble-metal nanocrescent arrays,” Nanotechnology 19, 145305 (2008).
[CrossRef]

Vollmer, M.

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

Volpe, G.

A. G. Curto, G. Volpe, T. H. Taminiau, M. P. Kreuzer, R. Quidant, and N. F. Van Hulst, “Unidirectional emission of a quantum dot coupled to a nanoantenna,” Science 329, 930–933 (2010).
[CrossRef]

Wang, Q. J.

Wu, L. Y.

L. Y. Wu, B. M. Ross, and L. P. Lee, “Optical properties of the crescent-shaped nanohole antenna,” Nano Lett. 9, 1956–1961 (2009).
[CrossRef]

Xie, S.

Xu, H.

Xu, X.

Xu, Z. Z.

Y. Zhang, T. Q. Jia, D. H. Feng, and Z. Z. Xu, “Quadrupole plasmon resonance mode in nanocrescent/nanodisk structure: local field enhancement and tunability in the visible light region,” Appl. Phys. Lett. 98, 163110 (2011).
[CrossRef]

Yu, L.

L. Yu, G. L. Liu, J. Kim, Y. X. Mejia, and L. P. Lee, “Nanophotonic crescent moon structures with sharp edge for ultrasensitive biomolecular detection by local electromagnetic field enhancement effect,” Nano Lett. 5, 119–124 (2005).
[CrossRef]

Zhang, D.

B. Pettinger, K. F. Domke, D. Zhang, G. Picardi, and R. Schuster, “Tip-enhanced Raman scattering: influence of the tip-surface geometry on optical resonance and enhancement,” Surf. Sci. 603, 1335–1341 (2009).
[CrossRef]

B. Pettinger, K. F. Domke, D. Zhang, R. Schuster, and G. Ertl, “Direct monitoring of plasmon resonances in a tip-surface gap of varying width,” Phys. Rev. B 76, 113409 (2007).
[CrossRef]

Zhang, S.

Zhang, Y.

Y. Zhang, T. Q. Jia, D. H. Feng, and Z. Z. Xu, “Quadrupole plasmon resonance mode in nanocrescent/nanodisk structure: local field enhancement and tunability in the visible light region,” Appl. Phys. Lett. 98, 163110 (2011).
[CrossRef]

Zhao, J.

J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7, 442–453 (2008).
[CrossRef]

Zhou, X.

ACS Nano (1)

R. Bukasov, T. A. Ali, P. Nordlander, and J. S. Shumaker-Parry, “Probing the plasmonic near-field of gold nanocrescent antennas,” ACS Nano 4, 6639–6650 (2010).
[CrossRef]

Adv. Mater. (2)

G. L. Liu, Y. Lu, J. Kim, J. C. Doll, and L. P. Lee, “Magnetic nanocrescents as controllable surface-enhanced Raman scattering nanoprobes for biomolecular imaging,” Adv. Mater. 17, 2683–2688 (2005).
[CrossRef]

J. S. Shumaker-Parry, H. Rochholz, and M. Kreiter, “Fabrication of crescent-shaped optical antennas,” Adv. Mater. 17, 2131–2134 (2005).
[CrossRef]

Adv. Opt. Photon. (1)

Anal. Chem. (1)

G. Moula and R. F. Aroca, “Plasmon-enhanced resonance Raman scattering and fluorescence in Langmuir–Blodgett monolayers,” Anal. Chem. 83, 284–288 (2011).
[CrossRef]

Appl. Opt. (2)

Appl. Phys. Lett. (1)

Y. Zhang, T. Q. Jia, D. H. Feng, and Z. Z. Xu, “Quadrupole plasmon resonance mode in nanocrescent/nanodisk structure: local field enhancement and tunability in the visible light region,” Appl. Phys. Lett. 98, 163110 (2011).
[CrossRef]

Chem. Rev. (1)

N. J. Halas, S. Lal, W. S. Chang, S. Link, and P. Nordlander, “Plasmons in strongly coupled metallic nanostructures,” Chem. Rev. 111, 3913–3961 (2011).
[CrossRef]

J. Opt. Soc. Am. A (2)

Laser Photon. Rev. (1)

M. Pelton, J. Aizpurua, and G. Bryant, “Metal–nanoparticle plasmonics,” Laser Photon. Rev. 2, 136–159 (2008).
[CrossRef]

Nano Lett. (5)

A. Aubry, D. Y. Lei, A. I. Fernandez-Dominguez, Y. Sonnefraud, S. A. Maier, and J. B. Pendry, “Plasmonic light-harvesting devices over the whole visible spectrum,” Nano Lett. 10, 2574–2579 (2010).
[CrossRef]

L. Yu, G. L. Liu, J. Kim, Y. X. Mejia, and L. P. Lee, “Nanophotonic crescent moon structures with sharp edge for ultrasensitive biomolecular detection by local electromagnetic field enhancement effect,” Nano Lett. 5, 119–124 (2005).
[CrossRef]

R. Bukasov and J. S. Shumaker-Parry, “Highly tunable infrared extinction properties of gold nanocrescents,” Nano Lett. 7, 1113–1118 (2007).
[CrossRef]

A. Unger, U. Rietzler, R. Berger, and M. Kreiter, “Sensitivity of crescent-shaped metal nanoparticles to attachment of dielectric colloids,” Nano Lett. 9, 2311–2315 (2009).
[CrossRef]

L. Y. Wu, B. M. Ross, and L. P. Lee, “Optical properties of the crescent-shaped nanohole antenna,” Nano Lett. 9, 1956–1961 (2009).
[CrossRef]

Nanotechnology (2)

B. M. Ross and L. P. Lee, “Plasmon tuning and local field enhancement maximization of the nanocrescent,” Nanotechnology 19, 275201 (2008).
[CrossRef]

K. Li, L. Clime, B. Cui, and T. Veres, “Surface enhanced Raman scattering on long-range ordered noble-metal nanocrescent arrays,” Nanotechnology 19, 145305 (2008).
[CrossRef]

Nat. Mater. (1)

J. N. Anker, W. P. Hall, O. Lyandres, N. C. Shah, J. Zhao, and R. P. Van Duyne, “Biosensing with plasmonic nanosensors,” Nat. Mater. 7, 442–453 (2008).
[CrossRef]

Nat. Photon. (1)

A. Alu and N. Engheta, “Tuning the scattering response of optical nanoantennas with nanocircuit loads,” Nat. Photon. 2, 307–310 (2008).
[CrossRef]

Nature (1)

W. L. Barnes, A. Dereux, and T. W. Ebbesen, “Surface plasmon subwavelength optics,” Nature 424, 824–830 (2003).
[CrossRef]

New J. Phys. (1)

H. Rochholz, N. Bocchio, and M. Kreiter, “Tuning resonances on crescent-shaped noble-metal nanoparticles,” New J. Phys. 9, 53 (2007).
[CrossRef]

Opt. Express (1)

Phys. Rev. B (3)

A. Aubry, D. Y. Lei, S. A. Maier, and J. B. Pendry, “Broadband plasmonic device concentrating the energy at the nanoscale: the crescent-shaped cylinder,” Phys. Rev. B 82, 125430 (2010).
[CrossRef]

B. Pettinger, K. F. Domke, D. Zhang, R. Schuster, and G. Ertl, “Direct monitoring of plasmon resonances in a tip-surface gap of varying width,” Phys. Rev. B 76, 113409 (2007).
[CrossRef]

P. B. Johnson and R. W. Christy, “Optical constants of the noble metals,” Phys. Rev. B 6, 4370–4379 (1972).
[CrossRef]

Phys. Rev. Lett. (2)

R. Berndt, J. K. Gimzewski, and P. Johansson, “Electromagnetic interactions of metallic objects in nanometer proximity,” Phys. Rev. Lett. 71, 3493–3496 (1993).
[CrossRef]

A. Alu and N. Engheta, “Input impedance, nanocircuit loading, and radiation tuning of optical nanoantennas,” Phys. Rev. Lett. 101, 043901 (2008).
[CrossRef]

Rev. Mod. Phys. (1)

M. Moskovits, “Surface-enhanced spectroscopy,” Rev. Mod. Phys. 57, 783–826 (1985).
[CrossRef]

Sci. Am. (1)

H. A. Atwater, “The promise of plasmonics,” Sci. Am. 296, 56–62 (2007).
[CrossRef]

Science (1)

A. G. Curto, G. Volpe, T. H. Taminiau, M. P. Kreuzer, R. Quidant, and N. F. Van Hulst, “Unidirectional emission of a quantum dot coupled to a nanoantenna,” Science 329, 930–933 (2010).
[CrossRef]

Surf. Sci. (1)

B. Pettinger, K. F. Domke, D. Zhang, G. Picardi, and R. Schuster, “Tip-enhanced Raman scattering: influence of the tip-surface geometry on optical resonance and enhancement,” Surf. Sci. 603, 1335–1341 (2009).
[CrossRef]

Other (6)

E. C. Le Ru and P. G. Etchegoin, Principles of Surface-Enhanced Raman Spectroscopy and Related Plasmonic Effects (Elsevier, 2009).

H. Raether, Surface Plasmons on Smooth and Rough Surfaces and on Gratings (Springer, 1988).

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

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

L. Novotny and B. Hecht, Principles of Nano-Optics (Cambridge University, 2006).

S. Kawata and V. M. Shalaev, eds., Tip Enhancement (Elsevier, 2007).

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (5)

Fig. 1.
Fig. 1.

(a) Schematic of the NCNS geometry with key parameters. The incident electromagnetic radiation is TM polarized plane with their representative k and E vector as indicated by arrows. The evaluation of near-field enhancement was performed at point p. (b) 3D depiction of the NCNS geometry.

Fig. 2.
Fig. 2.

(a) Near-field enhancement comparison between nanocresent and nanocresent-nanostrip structures. Optical near-field distribution of nanocrescent cylinder for resonant wavelengths (b) 580 and (c) 850 nm. Optical near-field distribution of NCNS for resonant wavelengths (d) 580 and (e) 1140 nm. The arrow in (b) represents the direction of incidence and was constant for all the other near-field optical maps.

Fig. 3.
Fig. 3.

Tunable resonance in the NCNS structure. (a) Shift in the near-field enhancement spectrum as function of the gap (g) between the nanocresent and nanostrip. (b) Variation of resonance peak position and near-field enhancement as a function of g.

Fig. 4.
Fig. 4.

Tunable resonance in NCNS structure. (a) Shift in the near-field enhancement spectrum as a function of length (l) of the nanostrip in NCNS and (b) variation of resonance peak position and near-field enhancement as function of l.

Fig. 5.
Fig. 5.

Variation of near-field enhancement as a function of excitation angle evaluated at the monitor point p in the NCNS geometry. (a) Polar plot of near-field enhancement as a function of the excitation angle for the two resonances at 1140 nm (red circles) and 580 nm (black squares). Near-field distribution maps for excitation angles at (b) 45°, (c) 90°, (d) 180°, and (e) 270°. The wavelength of excitation for cases (b)–(e) is at 1140 nm. The white arrow indicates the illumination direction.

Metrics