Abstract

Optical antennas have been widely used for sensitive photodetection, efficient light emission, high resolution imaging, and biochemical sensing because of their ability to capture and focus light energy beyond the diffraction limit. However, widespread application of optical antennas has been limited due to lack of appropriate methods for uniform and large area fabrication of antennas as well as difficulty in achieving an efficient design with small mode volume (gap spacing < 10nm). Here, we present a novel optical antenna design, arch-dipole antenna, with optimal radiation efficiency and small mode volume, 5 nm gap spacing, fabricated by CMOS-compatible deep-UV spacer lithography. We demonstrate strong surface-enhanced Raman spectroscopy (SERS) signal with an enhancement factor exceeding 108 from the arch-dipole antenna array, which is two orders of magnitude stronger than that from the standard dipole antenna array fabricated by e-beam lithography. Since the antenna gap spacing, the critical dimension of the antenna, can be defined by deep-UV lithography, efficient optical antenna arrays with nanometer-scale gap can be mass-produced using current CMOS technology.

© 2013 OSA

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  1. K. B. Crozier, A. Sundaramurthy, G. S. Kino, and C. F. Quate, “Optical antennas: Resonators for local field enhancement,” J. Appl. Phys.94(7), 4632 (2003).
    [CrossRef]
  2. P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, “Resonant optical antennas,” Science308(5728), 1607–1609 (2005).
    [CrossRef] [PubMed]
  3. L. Novotny and N. van Hulst, “Antennas for light,” Nat. Photonics5(2), 83–90 (2011).
    [CrossRef]
  4. V. Giannini, A. I. Fernández-Domínguez, S. C. Heck, and S. A. Maier, “Plasmonic nanoantennas: fundamentals and their use in controlling the radiative properties of nanoemitters,” Chem. Rev.111(6), 3888–3912 (2011).
    [CrossRef] [PubMed]
  5. L. Tang, S. E. Kocabas, S. Latif, A. K. Okyay, D.-S. Ly-Gagnon, K. C. Saraswat, and D. A. B. Miller, “Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna,” Nat. Photonics2(4), 226–229 (2008).
    [CrossRef]
  6. P. Fan, K. C. Y. Huang, L. Cao, and M. L. Brongersma, “Redesigning photodetector electrodes as an optical antenna,” Nano Lett.13(2), 392–396 (2013).
    [CrossRef] [PubMed]
  7. A. Kinkhabwala, Z. Yu, S. Fan, Y. Avlasevich, K. Mullen, and W. E. Moerner, “Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna,” Nat. Photonics3(11), 654–657 (2009).
    [CrossRef]
  8. K. J. Russell, T.-L. Liu, S. Cui, and E. L. Hu, “Large spontaneous emission enhancement in plasmonic nanocavities,” Nat. Photonics6(7), 459–462 (2012).
    [CrossRef]
  9. M. P. Busson, B. Rolly, B. Stout, N. Bonod, and S. Bidault, “Accelerated single photon emission from dye molecule-driven nanoantennas assembled on DNA,” Nat Commun3, 962 (2012).
    [CrossRef] [PubMed]
  10. K. C. Y. Huang, M.-K. Seo, Y. Huo, T. Sarmiento, J. S. Harris, and M. L. Brongersma, “Antenna electrodes for controlling electroluminescence,” Nat Commun3, 1005 (2012).
    [CrossRef] [PubMed]
  11. C. Höppener and L. Novotny, “Antenna-based optical imaging of single Ca2+ transmembrane proteins in liquids,” Nano Lett.8(2), 642–646 (2008).
    [CrossRef] [PubMed]
  12. T. S. van Zanten, M. J. Lopez-Bosque, and M. F. Garcia-Parajo, “Imaging individual proteins and nanodomains on intact cell membranes with a probe-based optical antenna,” Small6(2), 270–275 (2010).
    [CrossRef] [PubMed]
  13. W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
    [CrossRef]
  14. D. P. Fromm, A. Sundaramurthy, A. Kinkhabwala, P. J. Schuck, G. S. Kino, and W. E. Moerner, “Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas,” J. Chem. Phys.124(6), 061101 (2006).
    [CrossRef] [PubMed]
  15. W. Zhu, M. G. Banaee, D. Wang, Y. Chu, and K. B. Crozier, “Lithographically fabricated optical antennas with gaps well below 10 nm,” Small7(13), 1761–1766 (2011).
    [CrossRef] [PubMed]
  16. A. Ahmed and R. Gordon, “Single molecule directivity enhanced raman scattering using nanoantennas,” Nano Lett.12(5), 2625–2630 (2012).
    [CrossRef] [PubMed]
  17. P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, and W. E. Moerner, “Improving the mismatch between light and nanoscale objects with gold bowtie nanoantennas,” Phys. Rev. Lett.94(1), 017402 (2005).
    [CrossRef] [PubMed]
  18. M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
    [CrossRef] [PubMed]
  19. Y.-K. Choi, T.-J. King, and C. Hu, “A spacer patterning technology for nanoscale CMOS,” IEEE Trans. Electron Devices49(3), 436–441 (2002).
    [CrossRef]
  20. Y.-K. Choi, J. Zhu, J. Grunes, J. Bokor, and G. A. Somorjai, “Fabrication of Sub-10-nm silicon nanowire arrays by size reduction lithography,” J. Phys. Chem. B107(15), 3340–3343 (2003).
    [CrossRef]
  21. T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
    [CrossRef] [PubMed]
  22. S. A. Maier, “Plasmonic field enhancement and SERS in the effective mode volume picture,” Opt. Express14(5), 1957–1964 (2006).
    [CrossRef] [PubMed]
  23. T. Feichtner, O. Selig, M. Kiunke, and B. Hecht, “Evolutionary optimization of optical antennas,” Phys. Rev. Lett.109(12), 127701 (2012).
    [CrossRef] [PubMed]
  24. M. Fleischmann, P. J. Hendra, and A. J. McQuillan, “Raman spectra of pyridine adsorbed at a silver electrode,” Chem. Phys. Lett.26(2), 163–166 (1974).
    [CrossRef]
  25. D. L. Jeanmaire and R. P. Van Duyne, “Surface raman spectroelectrochemistry: Part I. Heterocyclic, aromatic, and aliphatic amines adsorbed on the anodized silver electrode,” J. Electroanal. Chem. Interfacial Electrochem.84(1), 1–20 (1977).
    [CrossRef]
  26. 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(9), 1667–1670 (1997).
    [CrossRef]
  27. S. Nie and S. R. Emory, “Probing single molecules and single nanoparticles by Surface-Enhanced Raman Scattering,” Science275(5303), 1102–1106 (1997).
    [CrossRef] [PubMed]
  28. D.-K. Lim, K.-S. Jeon, H. M. Kim, J.-M. Nam, and Y. D. Suh, “Nanogap-engineerable Raman-active nanodumbbells for single-molecule detection,” Nat. Mater.9(1), 60–67 (2010).
    [CrossRef] [PubMed]
  29. D.-K. Lim, K.-S. Jeon, J.-H. Hwang, H. Kim, S. Kwon, Y. D. Suh, and J.-M. Nam, “Highly uniform and reproducible surface-enhanced Raman scattering from DNA-tailorable nanoparticles with 1-nm interior gap,” Nat. Nanotechnol.6(7), 452–460 (2011).
    [CrossRef] [PubMed]
  30. Y. Fang, N.-H. Seong, and D. D. Dlott, “Measurement of the distribution of site enhancements in Surface-Enhanced Raman Scattering,” Science321(5887), 388–392 (2008).
    [CrossRef] [PubMed]

2013

P. Fan, K. C. Y. Huang, L. Cao, and M. L. Brongersma, “Redesigning photodetector electrodes as an optical antenna,” Nano Lett.13(2), 392–396 (2013).
[CrossRef] [PubMed]

2012

A. Ahmed and R. Gordon, “Single molecule directivity enhanced raman scattering using nanoantennas,” Nano Lett.12(5), 2625–2630 (2012).
[CrossRef] [PubMed]

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[CrossRef] [PubMed]

K. J. Russell, T.-L. Liu, S. Cui, and E. L. Hu, “Large spontaneous emission enhancement in plasmonic nanocavities,” Nat. Photonics6(7), 459–462 (2012).
[CrossRef]

M. P. Busson, B. Rolly, B. Stout, N. Bonod, and S. Bidault, “Accelerated single photon emission from dye molecule-driven nanoantennas assembled on DNA,” Nat Commun3, 962 (2012).
[CrossRef] [PubMed]

K. C. Y. Huang, M.-K. Seo, Y. Huo, T. Sarmiento, J. S. Harris, and M. L. Brongersma, “Antenna electrodes for controlling electroluminescence,” Nat Commun3, 1005 (2012).
[CrossRef] [PubMed]

T. Feichtner, O. Selig, M. Kiunke, and B. Hecht, “Evolutionary optimization of optical antennas,” Phys. Rev. Lett.109(12), 127701 (2012).
[CrossRef] [PubMed]

2011

W. Zhu, M. G. Banaee, D. Wang, Y. Chu, and K. B. Crozier, “Lithographically fabricated optical antennas with gaps well below 10 nm,” Small7(13), 1761–1766 (2011).
[CrossRef] [PubMed]

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

D.-K. Lim, K.-S. Jeon, J.-H. Hwang, H. Kim, S. Kwon, Y. D. Suh, and J.-M. Nam, “Highly uniform and reproducible surface-enhanced Raman scattering from DNA-tailorable nanoparticles with 1-nm interior gap,” Nat. Nanotechnol.6(7), 452–460 (2011).
[CrossRef] [PubMed]

L. Novotny and N. van Hulst, “Antennas for light,” Nat. Photonics5(2), 83–90 (2011).
[CrossRef]

V. Giannini, A. I. Fernández-Domínguez, S. C. Heck, and S. A. Maier, “Plasmonic nanoantennas: fundamentals and their use in controlling the radiative properties of nanoemitters,” Chem. Rev.111(6), 3888–3912 (2011).
[CrossRef] [PubMed]

2010

T. S. van Zanten, M. J. Lopez-Bosque, and M. F. Garcia-Parajo, “Imaging individual proteins and nanodomains on intact cell membranes with a probe-based optical antenna,” Small6(2), 270–275 (2010).
[CrossRef] [PubMed]

D.-K. Lim, K.-S. Jeon, H. M. Kim, J.-M. Nam, and Y. D. Suh, “Nanogap-engineerable Raman-active nanodumbbells for single-molecule detection,” Nat. Mater.9(1), 60–67 (2010).
[CrossRef] [PubMed]

2009

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

A. Kinkhabwala, Z. Yu, S. Fan, Y. Avlasevich, K. Mullen, and W. E. Moerner, “Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna,” Nat. Photonics3(11), 654–657 (2009).
[CrossRef]

2008

L. Tang, S. E. Kocabas, S. Latif, A. K. Okyay, D.-S. Ly-Gagnon, K. C. Saraswat, and D. A. B. Miller, “Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna,” Nat. Photonics2(4), 226–229 (2008).
[CrossRef]

C. Höppener and L. Novotny, “Antenna-based optical imaging of single Ca2+ transmembrane proteins in liquids,” Nano Lett.8(2), 642–646 (2008).
[CrossRef] [PubMed]

Y. Fang, N.-H. Seong, and D. D. Dlott, “Measurement of the distribution of site enhancements in Surface-Enhanced Raman Scattering,” Science321(5887), 388–392 (2008).
[CrossRef] [PubMed]

2006

S. A. Maier, “Plasmonic field enhancement and SERS in the effective mode volume picture,” Opt. Express14(5), 1957–1964 (2006).
[CrossRef] [PubMed]

D. P. Fromm, A. Sundaramurthy, A. Kinkhabwala, P. J. Schuck, G. S. Kino, and W. E. Moerner, “Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas,” J. Chem. Phys.124(6), 061101 (2006).
[CrossRef] [PubMed]

2005

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, and W. E. Moerner, “Improving the mismatch between light and nanoscale objects with gold bowtie nanoantennas,” Phys. Rev. Lett.94(1), 017402 (2005).
[CrossRef] [PubMed]

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, “Resonant optical antennas,” Science308(5728), 1607–1609 (2005).
[CrossRef] [PubMed]

2003

K. B. Crozier, A. Sundaramurthy, G. S. Kino, and C. F. Quate, “Optical antennas: Resonators for local field enhancement,” J. Appl. Phys.94(7), 4632 (2003).
[CrossRef]

Y.-K. Choi, J. Zhu, J. Grunes, J. Bokor, and G. A. Somorjai, “Fabrication of Sub-10-nm silicon nanowire arrays by size reduction lithography,” J. Phys. Chem. B107(15), 3340–3343 (2003).
[CrossRef]

2002

Y.-K. Choi, T.-J. King, and C. Hu, “A spacer patterning technology for nanoscale CMOS,” IEEE Trans. Electron Devices49(3), 436–441 (2002).
[CrossRef]

1997

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(9), 1667–1670 (1997).
[CrossRef]

S. Nie and S. R. Emory, “Probing single molecules and single nanoparticles by Surface-Enhanced Raman Scattering,” Science275(5303), 1102–1106 (1997).
[CrossRef] [PubMed]

1977

D. L. Jeanmaire and R. P. Van Duyne, “Surface raman spectroelectrochemistry: Part I. Heterocyclic, aromatic, and aliphatic amines adsorbed on the anodized silver electrode,” J. Electroanal. Chem. Interfacial Electrochem.84(1), 1–20 (1977).
[CrossRef]

1974

M. Fleischmann, P. J. Hendra, and A. J. McQuillan, “Raman spectra of pyridine adsorbed at a silver electrode,” Chem. Phys. Lett.26(2), 163–166 (1974).
[CrossRef]

Ahmed, A.

A. Ahmed and R. Gordon, “Single molecule directivity enhanced raman scattering using nanoantennas,” Nano Lett.12(5), 2625–2630 (2012).
[CrossRef] [PubMed]

Avlasevich, Y.

A. Kinkhabwala, Z. Yu, S. Fan, Y. Avlasevich, K. Mullen, and W. E. Moerner, “Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna,” Nat. Photonics3(11), 654–657 (2009).
[CrossRef]

Banaee, M. G.

W. Zhu, M. G. Banaee, D. Wang, Y. Chu, and K. B. Crozier, “Lithographically fabricated optical antennas with gaps well below 10 nm,” Small7(13), 1761–1766 (2011).
[CrossRef] [PubMed]

Bidault, S.

M. P. Busson, B. Rolly, B. Stout, N. Bonod, and S. Bidault, “Accelerated single photon emission from dye molecule-driven nanoantennas assembled on DNA,” Nat Commun3, 962 (2012).
[CrossRef] [PubMed]

Bokor, J.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

Y.-K. Choi, J. Zhu, J. Grunes, J. Bokor, and G. A. Somorjai, “Fabrication of Sub-10-nm silicon nanowire arrays by size reduction lithography,” J. Phys. Chem. B107(15), 3340–3343 (2003).
[CrossRef]

Bonod, N.

M. P. Busson, B. Rolly, B. Stout, N. Bonod, and S. Bidault, “Accelerated single photon emission from dye molecule-driven nanoantennas assembled on DNA,” Nat Commun3, 962 (2012).
[CrossRef] [PubMed]

Brongersma, M. L.

P. Fan, K. C. Y. Huang, L. Cao, and M. L. Brongersma, “Redesigning photodetector electrodes as an optical antenna,” Nano Lett.13(2), 392–396 (2013).
[CrossRef] [PubMed]

K. C. Y. Huang, M.-K. Seo, Y. Huo, T. Sarmiento, J. S. Harris, and M. L. Brongersma, “Antenna electrodes for controlling electroluminescence,” Nat Commun3, 1005 (2012).
[CrossRef] [PubMed]

Brown, L.

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[CrossRef] [PubMed]

Busson, M. P.

M. P. Busson, B. Rolly, B. Stout, N. Bonod, and S. Bidault, “Accelerated single photon emission from dye molecule-driven nanoantennas assembled on DNA,” Nat Commun3, 962 (2012).
[CrossRef] [PubMed]

Cabrini, S.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

Cao, L.

P. Fan, K. C. Y. Huang, L. Cao, and M. L. Brongersma, “Redesigning photodetector electrodes as an optical antenna,” Nano Lett.13(2), 392–396 (2013).
[CrossRef] [PubMed]

Challener, W. A.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Choi, Y.-K.

Y.-K. Choi, J. Zhu, J. Grunes, J. Bokor, and G. A. Somorjai, “Fabrication of Sub-10-nm silicon nanowire arrays by size reduction lithography,” J. Phys. Chem. B107(15), 3340–3343 (2003).
[CrossRef]

Y.-K. Choi, T.-J. King, and C. Hu, “A spacer patterning technology for nanoscale CMOS,” IEEE Trans. Electron Devices49(3), 436–441 (2002).
[CrossRef]

Choo, H.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

Chu, Y.

W. Zhu, M. G. Banaee, D. Wang, Y. Chu, and K. B. Crozier, “Lithographically fabricated optical antennas with gaps well below 10 nm,” Small7(13), 1761–1766 (2011).
[CrossRef] [PubMed]

Crozier, K. B.

W. Zhu, M. G. Banaee, D. Wang, Y. Chu, and K. B. Crozier, “Lithographically fabricated optical antennas with gaps well below 10 nm,” Small7(13), 1761–1766 (2011).
[CrossRef] [PubMed]

K. B. Crozier, A. Sundaramurthy, G. S. Kino, and C. F. Quate, “Optical antennas: Resonators for local field enhancement,” J. Appl. Phys.94(7), 4632 (2003).
[CrossRef]

Cui, S.

K. J. Russell, T.-L. Liu, S. Cui, and E. L. Hu, “Large spontaneous emission enhancement in plasmonic nanocavities,” Nat. Photonics6(7), 459–462 (2012).
[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(9), 1667–1670 (1997).
[CrossRef]

Dhuey, S.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

Dlott, D. D.

Y. Fang, N.-H. Seong, and D. D. Dlott, “Measurement of the distribution of site enhancements in Surface-Enhanced Raman Scattering,” Science321(5887), 388–392 (2008).
[CrossRef] [PubMed]

Eisler, H.-J.

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, “Resonant optical antennas,” Science308(5728), 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,” Science275(5303), 1102–1106 (1997).
[CrossRef] [PubMed]

Everitt, H. O.

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[CrossRef] [PubMed]

Fan, P.

P. Fan, K. C. Y. Huang, L. Cao, and M. L. Brongersma, “Redesigning photodetector electrodes as an optical antenna,” Nano Lett.13(2), 392–396 (2013).
[CrossRef] [PubMed]

Fan, S.

A. Kinkhabwala, Z. Yu, S. Fan, Y. Avlasevich, K. Mullen, and W. E. Moerner, “Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna,” Nat. Photonics3(11), 654–657 (2009).
[CrossRef]

Fang, Y.

Y. Fang, N.-H. Seong, and D. D. Dlott, “Measurement of the distribution of site enhancements in Surface-Enhanced Raman Scattering,” Science321(5887), 388–392 (2008).
[CrossRef] [PubMed]

Feichtner, T.

T. Feichtner, O. Selig, M. Kiunke, and B. Hecht, “Evolutionary optimization of optical antennas,” Phys. Rev. Lett.109(12), 127701 (2012).
[CrossRef] [PubMed]

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(9), 1667–1670 (1997).
[CrossRef]

Fernández-Domínguez, A. I.

V. Giannini, A. I. Fernández-Domínguez, S. C. Heck, and S. A. Maier, “Plasmonic nanoantennas: fundamentals and their use in controlling the radiative properties of nanoemitters,” Chem. Rev.111(6), 3888–3912 (2011).
[CrossRef] [PubMed]

Fleischmann, M.

M. Fleischmann, P. J. Hendra, and A. J. McQuillan, “Raman spectra of pyridine adsorbed at a silver electrode,” Chem. Phys. Lett.26(2), 163–166 (1974).
[CrossRef]

Fromm, D. P.

D. P. Fromm, A. Sundaramurthy, A. Kinkhabwala, P. J. Schuck, G. S. Kino, and W. E. Moerner, “Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas,” J. Chem. Phys.124(6), 061101 (2006).
[CrossRef] [PubMed]

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, and W. E. Moerner, “Improving the mismatch between light and nanoscale objects with gold bowtie nanoantennas,” Phys. Rev. Lett.94(1), 017402 (2005).
[CrossRef] [PubMed]

Gage, E. C.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Garcia-Parajo, M. F.

T. S. van Zanten, M. J. Lopez-Bosque, and M. F. Garcia-Parajo, “Imaging individual proteins and nanodomains on intact cell membranes with a probe-based optical antenna,” Small6(2), 270–275 (2010).
[CrossRef] [PubMed]

Giannini, V.

V. Giannini, A. I. Fernández-Domínguez, S. C. Heck, and S. A. Maier, “Plasmonic nanoantennas: fundamentals and their use in controlling the radiative properties of nanoemitters,” Chem. Rev.111(6), 3888–3912 (2011).
[CrossRef] [PubMed]

Gokemeijer, N. J.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Gordon, R.

A. Ahmed and R. Gordon, “Single molecule directivity enhanced raman scattering using nanoantennas,” Nano Lett.12(5), 2625–2630 (2012).
[CrossRef] [PubMed]

Grunes, J.

Y.-K. Choi, J. Zhu, J. Grunes, J. Bokor, and G. A. Somorjai, “Fabrication of Sub-10-nm silicon nanowire arrays by size reduction lithography,” J. Phys. Chem. B107(15), 3340–3343 (2003).
[CrossRef]

Halas, N. J.

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[CrossRef] [PubMed]

Harris, J. S.

K. C. Y. Huang, M.-K. Seo, Y. Huo, T. Sarmiento, J. S. Harris, and M. L. Brongersma, “Antenna electrodes for controlling electroluminescence,” Nat Commun3, 1005 (2012).
[CrossRef] [PubMed]

Hecht, B.

T. Feichtner, O. Selig, M. Kiunke, and B. Hecht, “Evolutionary optimization of optical antennas,” Phys. Rev. Lett.109(12), 127701 (2012).
[CrossRef] [PubMed]

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, “Resonant optical antennas,” Science308(5728), 1607–1609 (2005).
[CrossRef] [PubMed]

Heck, S. C.

V. Giannini, A. I. Fernández-Domínguez, S. C. Heck, and S. A. Maier, “Plasmonic nanoantennas: fundamentals and their use in controlling the radiative properties of nanoemitters,” Chem. Rev.111(6), 3888–3912 (2011).
[CrossRef] [PubMed]

Hendra, P. J.

M. Fleischmann, P. J. Hendra, and A. J. McQuillan, “Raman spectra of pyridine adsorbed at a silver electrode,” Chem. Phys. Lett.26(2), 163–166 (1974).
[CrossRef]

Höppener, C.

C. Höppener and L. Novotny, “Antenna-based optical imaging of single Ca2+ transmembrane proteins in liquids,” Nano Lett.8(2), 642–646 (2008).
[CrossRef] [PubMed]

Hsia, Y.-T.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Hu, C.

Y.-K. Choi, T.-J. King, and C. Hu, “A spacer patterning technology for nanoscale CMOS,” IEEE Trans. Electron Devices49(3), 436–441 (2002).
[CrossRef]

Hu, E. L.

K. J. Russell, T.-L. Liu, S. Cui, and E. L. Hu, “Large spontaneous emission enhancement in plasmonic nanocavities,” Nat. Photonics6(7), 459–462 (2012).
[CrossRef]

Huang, K. C. Y.

P. Fan, K. C. Y. Huang, L. Cao, and M. L. Brongersma, “Redesigning photodetector electrodes as an optical antenna,” Nano Lett.13(2), 392–396 (2013).
[CrossRef] [PubMed]

K. C. Y. Huang, M.-K. Seo, Y. Huo, T. Sarmiento, J. S. Harris, and M. L. Brongersma, “Antenna electrodes for controlling electroluminescence,” Nat Commun3, 1005 (2012).
[CrossRef] [PubMed]

Huo, Y.

K. C. Y. Huang, M.-K. Seo, Y. Huo, T. Sarmiento, J. S. Harris, and M. L. Brongersma, “Antenna electrodes for controlling electroluminescence,” Nat Commun3, 1005 (2012).
[CrossRef] [PubMed]

Hwang, J.-H.

D.-K. Lim, K.-S. Jeon, J.-H. Hwang, H. Kim, S. Kwon, Y. D. Suh, and J.-M. Nam, “Highly uniform and reproducible surface-enhanced Raman scattering from DNA-tailorable nanoparticles with 1-nm interior gap,” Nat. Nanotechnol.6(7), 452–460 (2011).
[CrossRef] [PubMed]

Itagi, A. V.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[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(9), 1667–1670 (1997).
[CrossRef]

Jamshidi, A.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

Jeanmaire, D. L.

D. L. Jeanmaire and R. P. Van Duyne, “Surface raman spectroelectrochemistry: Part I. Heterocyclic, aromatic, and aliphatic amines adsorbed on the anodized silver electrode,” J. Electroanal. Chem. Interfacial Electrochem.84(1), 1–20 (1977).
[CrossRef]

Jeon, K.-S.

D.-K. Lim, K.-S. Jeon, J.-H. Hwang, H. Kim, S. Kwon, Y. D. Suh, and J.-M. Nam, “Highly uniform and reproducible surface-enhanced Raman scattering from DNA-tailorable nanoparticles with 1-nm interior gap,” Nat. Nanotechnol.6(7), 452–460 (2011).
[CrossRef] [PubMed]

D.-K. Lim, K.-S. Jeon, H. M. Kim, J.-M. Nam, and Y. D. Suh, “Nanogap-engineerable Raman-active nanodumbbells for single-molecule detection,” Nat. Mater.9(1), 60–67 (2010).
[CrossRef] [PubMed]

Ju, G.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Karns, D.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Kim, H.

D.-K. Lim, K.-S. Jeon, J.-H. Hwang, H. Kim, S. Kwon, Y. D. Suh, and J.-M. Nam, “Highly uniform and reproducible surface-enhanced Raman scattering from DNA-tailorable nanoparticles with 1-nm interior gap,” Nat. Nanotechnol.6(7), 452–460 (2011).
[CrossRef] [PubMed]

Kim, H. M.

D.-K. Lim, K.-S. Jeon, H. M. Kim, J.-M. Nam, and Y. D. Suh, “Nanogap-engineerable Raman-active nanodumbbells for single-molecule detection,” Nat. Mater.9(1), 60–67 (2010).
[CrossRef] [PubMed]

Kim, M.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

King, N. S.

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[CrossRef] [PubMed]

King, T.-J.

Y.-K. Choi, T.-J. King, and C. Hu, “A spacer patterning technology for nanoscale CMOS,” IEEE Trans. Electron Devices49(3), 436–441 (2002).
[CrossRef]

Kinkhabwala, A.

A. Kinkhabwala, Z. Yu, S. Fan, Y. Avlasevich, K. Mullen, and W. E. Moerner, “Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna,” Nat. Photonics3(11), 654–657 (2009).
[CrossRef]

D. P. Fromm, A. Sundaramurthy, A. Kinkhabwala, P. J. Schuck, G. S. Kino, and W. E. Moerner, “Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas,” J. Chem. Phys.124(6), 061101 (2006).
[CrossRef] [PubMed]

Kino, G. S.

D. P. Fromm, A. Sundaramurthy, A. Kinkhabwala, P. J. Schuck, G. S. Kino, and W. E. Moerner, “Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas,” J. Chem. Phys.124(6), 061101 (2006).
[CrossRef] [PubMed]

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, and W. E. Moerner, “Improving the mismatch between light and nanoscale objects with gold bowtie nanoantennas,” Phys. Rev. Lett.94(1), 017402 (2005).
[CrossRef] [PubMed]

K. B. Crozier, A. Sundaramurthy, G. S. Kino, and C. F. Quate, “Optical antennas: Resonators for local field enhancement,” J. Appl. Phys.94(7), 4632 (2003).
[CrossRef]

Kiunke, M.

T. Feichtner, O. Selig, M. Kiunke, and B. Hecht, “Evolutionary optimization of optical antennas,” Phys. Rev. Lett.109(12), 127701 (2012).
[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(9), 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(9), 1667–1670 (1997).
[CrossRef]

Knight, M. W.

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[CrossRef] [PubMed]

Kocabas, S. E.

L. Tang, S. E. Kocabas, S. Latif, A. K. Okyay, D.-S. Ly-Gagnon, K. C. Saraswat, and D. A. B. Miller, “Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna,” Nat. Photonics2(4), 226–229 (2008).
[CrossRef]

Kwon, S.

D.-K. Lim, K.-S. Jeon, J.-H. Hwang, H. Kim, S. Kwon, Y. D. Suh, and J.-M. Nam, “Highly uniform and reproducible surface-enhanced Raman scattering from DNA-tailorable nanoparticles with 1-nm interior gap,” Nat. Nanotechnol.6(7), 452–460 (2011).
[CrossRef] [PubMed]

Lakhani, A.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

Latif, S.

L. Tang, S. E. Kocabas, S. Latif, A. K. Okyay, D.-S. Ly-Gagnon, K. C. Saraswat, and D. A. B. Miller, “Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna,” Nat. Photonics2(4), 226–229 (2008).
[CrossRef]

Lim, D.-K.

D.-K. Lim, K.-S. Jeon, J.-H. Hwang, H. Kim, S. Kwon, Y. D. Suh, and J.-M. Nam, “Highly uniform and reproducible surface-enhanced Raman scattering from DNA-tailorable nanoparticles with 1-nm interior gap,” Nat. Nanotechnol.6(7), 452–460 (2011).
[CrossRef] [PubMed]

D.-K. Lim, K.-S. Jeon, H. M. Kim, J.-M. Nam, and Y. D. Suh, “Nanogap-engineerable Raman-active nanodumbbells for single-molecule detection,” Nat. Mater.9(1), 60–67 (2010).
[CrossRef] [PubMed]

Liu, L.

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[CrossRef] [PubMed]

Liu, T.-L.

K. J. Russell, T.-L. Liu, S. Cui, and E. L. Hu, “Large spontaneous emission enhancement in plasmonic nanocavities,” Nat. Photonics6(7), 459–462 (2012).
[CrossRef]

Lopez-Bosque, M. J.

T. S. van Zanten, M. J. Lopez-Bosque, and M. F. Garcia-Parajo, “Imaging individual proteins and nanodomains on intact cell membranes with a probe-based optical antenna,” Small6(2), 270–275 (2010).
[CrossRef] [PubMed]

Ly-Gagnon, D.-S.

L. Tang, S. E. Kocabas, S. Latif, A. K. Okyay, D.-S. Ly-Gagnon, K. C. Saraswat, and D. A. B. Miller, “Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna,” Nat. Photonics2(4), 226–229 (2008).
[CrossRef]

Maier, S. A.

V. Giannini, A. I. Fernández-Domínguez, S. C. Heck, and S. A. Maier, “Plasmonic nanoantennas: fundamentals and their use in controlling the radiative properties of nanoemitters,” Chem. Rev.111(6), 3888–3912 (2011).
[CrossRef] [PubMed]

S. A. Maier, “Plasmonic field enhancement and SERS in the effective mode volume picture,” Opt. Express14(5), 1957–1964 (2006).
[CrossRef] [PubMed]

Martin, O. J. F.

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, “Resonant optical antennas,” Science308(5728), 1607–1609 (2005).
[CrossRef] [PubMed]

McQuillan, A. J.

M. Fleischmann, P. J. Hendra, and A. J. McQuillan, “Raman spectra of pyridine adsorbed at a silver electrode,” Chem. Phys. Lett.26(2), 163–166 (1974).
[CrossRef]

Miller, D. A. B.

L. Tang, S. E. Kocabas, S. Latif, A. K. Okyay, D.-S. Ly-Gagnon, K. C. Saraswat, and D. A. B. Miller, “Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna,” Nat. Photonics2(4), 226–229 (2008).
[CrossRef]

Moerner, W. E.

A. Kinkhabwala, Z. Yu, S. Fan, Y. Avlasevich, K. Mullen, and W. E. Moerner, “Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna,” Nat. Photonics3(11), 654–657 (2009).
[CrossRef]

D. P. Fromm, A. Sundaramurthy, A. Kinkhabwala, P. J. Schuck, G. S. Kino, and W. E. Moerner, “Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas,” J. Chem. Phys.124(6), 061101 (2006).
[CrossRef] [PubMed]

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, and W. E. Moerner, “Improving the mismatch between light and nanoscale objects with gold bowtie nanoantennas,” Phys. Rev. Lett.94(1), 017402 (2005).
[CrossRef] [PubMed]

Mühlschlegel, P.

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, “Resonant optical antennas,” Science308(5728), 1607–1609 (2005).
[CrossRef] [PubMed]

Mukherjee, S.

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[CrossRef] [PubMed]

Mullen, K.

A. Kinkhabwala, Z. Yu, S. Fan, Y. Avlasevich, K. Mullen, and W. E. Moerner, “Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna,” Nat. Photonics3(11), 654–657 (2009).
[CrossRef]

Nam, J.-M.

D.-K. Lim, K.-S. Jeon, J.-H. Hwang, H. Kim, S. Kwon, Y. D. Suh, and J.-M. Nam, “Highly uniform and reproducible surface-enhanced Raman scattering from DNA-tailorable nanoparticles with 1-nm interior gap,” Nat. Nanotechnol.6(7), 452–460 (2011).
[CrossRef] [PubMed]

D.-K. Lim, K.-S. Jeon, H. M. Kim, J.-M. Nam, and Y. D. Suh, “Nanogap-engineerable Raman-active nanodumbbells for single-molecule detection,” Nat. Mater.9(1), 60–67 (2010).
[CrossRef] [PubMed]

Nie, S.

S. Nie and S. R. Emory, “Probing single molecules and single nanoparticles by Surface-Enhanced Raman Scattering,” Science275(5303), 1102–1106 (1997).
[CrossRef] [PubMed]

Nordlander, P.

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[CrossRef] [PubMed]

Novotny, L.

L. Novotny and N. van Hulst, “Antennas for light,” Nat. Photonics5(2), 83–90 (2011).
[CrossRef]

C. Höppener and L. Novotny, “Antenna-based optical imaging of single Ca2+ transmembrane proteins in liquids,” Nano Lett.8(2), 642–646 (2008).
[CrossRef] [PubMed]

Okyay, A. K.

L. Tang, S. E. Kocabas, S. Latif, A. K. Okyay, D.-S. Ly-Gagnon, K. C. Saraswat, and D. A. B. Miller, “Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna,” Nat. Photonics2(4), 226–229 (2008).
[CrossRef]

Peng, C.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Peng, W.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Peng, Y.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[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(9), 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,” Science308(5728), 1607–1609 (2005).
[CrossRef] [PubMed]

Quate, C. F.

K. B. Crozier, A. Sundaramurthy, G. S. Kino, and C. F. Quate, “Optical antennas: Resonators for local field enhancement,” J. Appl. Phys.94(7), 4632 (2003).
[CrossRef]

Rolly, B.

M. P. Busson, B. Rolly, B. Stout, N. Bonod, and S. Bidault, “Accelerated single photon emission from dye molecule-driven nanoantennas assembled on DNA,” Nat Commun3, 962 (2012).
[CrossRef] [PubMed]

Rottmayer, R. E.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Russell, K. J.

K. J. Russell, T.-L. Liu, S. Cui, and E. L. Hu, “Large spontaneous emission enhancement in plasmonic nanocavities,” Nat. Photonics6(7), 459–462 (2012).
[CrossRef]

Saraswat, K. C.

L. Tang, S. E. Kocabas, S. Latif, A. K. Okyay, D.-S. Ly-Gagnon, K. C. Saraswat, and D. A. B. Miller, “Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna,” Nat. Photonics2(4), 226–229 (2008).
[CrossRef]

Sarmiento, T.

K. C. Y. Huang, M.-K. Seo, Y. Huo, T. Sarmiento, J. S. Harris, and M. L. Brongersma, “Antenna electrodes for controlling electroluminescence,” Nat Commun3, 1005 (2012).
[CrossRef] [PubMed]

Schuck, P. J.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

D. P. Fromm, A. Sundaramurthy, A. Kinkhabwala, P. J. Schuck, G. S. Kino, and W. E. Moerner, “Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas,” J. Chem. Phys.124(6), 061101 (2006).
[CrossRef] [PubMed]

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, and W. E. Moerner, “Improving the mismatch between light and nanoscale objects with gold bowtie nanoantennas,” Phys. Rev. Lett.94(1), 017402 (2005).
[CrossRef] [PubMed]

Schwartzberg, A. M.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

Seigler, M. A.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Selig, O.

T. Feichtner, O. Selig, M. Kiunke, and B. Hecht, “Evolutionary optimization of optical antennas,” Phys. Rev. Lett.109(12), 127701 (2012).
[CrossRef] [PubMed]

Seo, M.-K.

K. C. Y. Huang, M.-K. Seo, Y. Huo, T. Sarmiento, J. S. Harris, and M. L. Brongersma, “Antenna electrodes for controlling electroluminescence,” Nat Commun3, 1005 (2012).
[CrossRef] [PubMed]

Seok, T. J.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

Seong, N.-H.

Y. Fang, N.-H. Seong, and D. D. Dlott, “Measurement of the distribution of site enhancements in Surface-Enhanced Raman Scattering,” Science321(5887), 388–392 (2008).
[CrossRef] [PubMed]

Somorjai, G. A.

Y.-K. Choi, J. Zhu, J. Grunes, J. Bokor, and G. A. Somorjai, “Fabrication of Sub-10-nm silicon nanowire arrays by size reduction lithography,” J. Phys. Chem. B107(15), 3340–3343 (2003).
[CrossRef]

Stout, B.

M. P. Busson, B. Rolly, B. Stout, N. Bonod, and S. Bidault, “Accelerated single photon emission from dye molecule-driven nanoantennas assembled on DNA,” Nat Commun3, 962 (2012).
[CrossRef] [PubMed]

Suh, Y. D.

D.-K. Lim, K.-S. Jeon, J.-H. Hwang, H. Kim, S. Kwon, Y. D. Suh, and J.-M. Nam, “Highly uniform and reproducible surface-enhanced Raman scattering from DNA-tailorable nanoparticles with 1-nm interior gap,” Nat. Nanotechnol.6(7), 452–460 (2011).
[CrossRef] [PubMed]

D.-K. Lim, K.-S. Jeon, H. M. Kim, J.-M. Nam, and Y. D. Suh, “Nanogap-engineerable Raman-active nanodumbbells for single-molecule detection,” Nat. Mater.9(1), 60–67 (2010).
[CrossRef] [PubMed]

Sundaramurthy, A.

D. P. Fromm, A. Sundaramurthy, A. Kinkhabwala, P. J. Schuck, G. S. Kino, and W. E. Moerner, “Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas,” J. Chem. Phys.124(6), 061101 (2006).
[CrossRef] [PubMed]

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, and W. E. Moerner, “Improving the mismatch between light and nanoscale objects with gold bowtie nanoantennas,” Phys. Rev. Lett.94(1), 017402 (2005).
[CrossRef] [PubMed]

K. B. Crozier, A. Sundaramurthy, G. S. Kino, and C. F. Quate, “Optical antennas: Resonators for local field enhancement,” J. Appl. Phys.94(7), 4632 (2003).
[CrossRef]

Tang, L.

L. Tang, S. E. Kocabas, S. Latif, A. K. Okyay, D.-S. Ly-Gagnon, K. C. Saraswat, and D. A. B. Miller, “Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna,” Nat. Photonics2(4), 226–229 (2008).
[CrossRef]

Van Duyne, R. P.

D. L. Jeanmaire and R. P. Van Duyne, “Surface raman spectroelectrochemistry: Part I. Heterocyclic, aromatic, and aliphatic amines adsorbed on the anodized silver electrode,” J. Electroanal. Chem. Interfacial Electrochem.84(1), 1–20 (1977).
[CrossRef]

van Hulst, N.

L. Novotny and N. van Hulst, “Antennas for light,” Nat. Photonics5(2), 83–90 (2011).
[CrossRef]

van Zanten, T. S.

T. S. van Zanten, M. J. Lopez-Bosque, and M. F. Garcia-Parajo, “Imaging individual proteins and nanodomains on intact cell membranes with a probe-based optical antenna,” Small6(2), 270–275 (2010).
[CrossRef] [PubMed]

Wang, D.

W. Zhu, M. G. Banaee, D. Wang, Y. Chu, and K. B. Crozier, “Lithographically fabricated optical antennas with gaps well below 10 nm,” Small7(13), 1761–1766 (2011).
[CrossRef] [PubMed]

Wang, Y.

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[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(9), 1667–1670 (1997).
[CrossRef]

Wu, M. C.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

Yablonovitch, E.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

Yang, X.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Yu, Z.

A. Kinkhabwala, Z. Yu, S. Fan, Y. Avlasevich, K. Mullen, and W. E. Moerner, “Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna,” Nat. Photonics3(11), 654–657 (2009).
[CrossRef]

Zhu, J.

Y.-K. Choi, J. Zhu, J. Grunes, J. Bokor, and G. A. Somorjai, “Fabrication of Sub-10-nm silicon nanowire arrays by size reduction lithography,” J. Phys. Chem. B107(15), 3340–3343 (2003).
[CrossRef]

Zhu, W.

W. Zhu, M. G. Banaee, D. Wang, Y. Chu, and K. B. Crozier, “Lithographically fabricated optical antennas with gaps well below 10 nm,” Small7(13), 1761–1766 (2011).
[CrossRef] [PubMed]

Zhu, X.

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Chem. Phys. Lett.

M. Fleischmann, P. J. Hendra, and A. J. McQuillan, “Raman spectra of pyridine adsorbed at a silver electrode,” Chem. Phys. Lett.26(2), 163–166 (1974).
[CrossRef]

Chem. Rev.

V. Giannini, A. I. Fernández-Domínguez, S. C. Heck, and S. A. Maier, “Plasmonic nanoantennas: fundamentals and their use in controlling the radiative properties of nanoemitters,” Chem. Rev.111(6), 3888–3912 (2011).
[CrossRef] [PubMed]

IEEE Trans. Electron Devices

Y.-K. Choi, T.-J. King, and C. Hu, “A spacer patterning technology for nanoscale CMOS,” IEEE Trans. Electron Devices49(3), 436–441 (2002).
[CrossRef]

J. Appl. Phys.

K. B. Crozier, A. Sundaramurthy, G. S. Kino, and C. F. Quate, “Optical antennas: Resonators for local field enhancement,” J. Appl. Phys.94(7), 4632 (2003).
[CrossRef]

J. Chem. Phys.

D. P. Fromm, A. Sundaramurthy, A. Kinkhabwala, P. J. Schuck, G. S. Kino, and W. E. Moerner, “Exploring the chemical enhancement for surface-enhanced Raman scattering with Au bowtie nanoantennas,” J. Chem. Phys.124(6), 061101 (2006).
[CrossRef] [PubMed]

J. Electroanal. Chem. Interfacial Electrochem.

D. L. Jeanmaire and R. P. Van Duyne, “Surface raman spectroelectrochemistry: Part I. Heterocyclic, aromatic, and aliphatic amines adsorbed on the anodized silver electrode,” J. Electroanal. Chem. Interfacial Electrochem.84(1), 1–20 (1977).
[CrossRef]

J. Phys. Chem. B

Y.-K. Choi, J. Zhu, J. Grunes, J. Bokor, and G. A. Somorjai, “Fabrication of Sub-10-nm silicon nanowire arrays by size reduction lithography,” J. Phys. Chem. B107(15), 3340–3343 (2003).
[CrossRef]

Nano Lett.

T. J. Seok, A. Jamshidi, M. Kim, S. Dhuey, A. Lakhani, H. Choo, P. J. Schuck, S. Cabrini, A. M. Schwartzberg, J. Bokor, E. Yablonovitch, and M. C. Wu, “Radiation engineering of optical antennas for maximum field enhancement,” Nano Lett.11(7), 2606–2610 (2011).
[CrossRef] [PubMed]

M. W. Knight, L. Liu, Y. Wang, L. Brown, S. Mukherjee, N. S. King, H. O. Everitt, P. Nordlander, and N. J. Halas, “Aluminum Plasmonic Nanoantennas,” Nano Lett.12(11), 6000–6004 (2012).
[CrossRef] [PubMed]

A. Ahmed and R. Gordon, “Single molecule directivity enhanced raman scattering using nanoantennas,” Nano Lett.12(5), 2625–2630 (2012).
[CrossRef] [PubMed]

C. Höppener and L. Novotny, “Antenna-based optical imaging of single Ca2+ transmembrane proteins in liquids,” Nano Lett.8(2), 642–646 (2008).
[CrossRef] [PubMed]

P. Fan, K. C. Y. Huang, L. Cao, and M. L. Brongersma, “Redesigning photodetector electrodes as an optical antenna,” Nano Lett.13(2), 392–396 (2013).
[CrossRef] [PubMed]

Nat Commun

M. P. Busson, B. Rolly, B. Stout, N. Bonod, and S. Bidault, “Accelerated single photon emission from dye molecule-driven nanoantennas assembled on DNA,” Nat Commun3, 962 (2012).
[CrossRef] [PubMed]

K. C. Y. Huang, M.-K. Seo, Y. Huo, T. Sarmiento, J. S. Harris, and M. L. Brongersma, “Antenna electrodes for controlling electroluminescence,” Nat Commun3, 1005 (2012).
[CrossRef] [PubMed]

Nat. Mater.

D.-K. Lim, K.-S. Jeon, H. M. Kim, J.-M. Nam, and Y. D. Suh, “Nanogap-engineerable Raman-active nanodumbbells for single-molecule detection,” Nat. Mater.9(1), 60–67 (2010).
[CrossRef] [PubMed]

Nat. Nanotechnol.

D.-K. Lim, K.-S. Jeon, J.-H. Hwang, H. Kim, S. Kwon, Y. D. Suh, and J.-M. Nam, “Highly uniform and reproducible surface-enhanced Raman scattering from DNA-tailorable nanoparticles with 1-nm interior gap,” Nat. Nanotechnol.6(7), 452–460 (2011).
[CrossRef] [PubMed]

Nat. Photonics

A. Kinkhabwala, Z. Yu, S. Fan, Y. Avlasevich, K. Mullen, and W. E. Moerner, “Large single-molecule fluorescence enhancements produced by a bowtie nanoantenna,” Nat. Photonics3(11), 654–657 (2009).
[CrossRef]

K. J. Russell, T.-L. Liu, S. Cui, and E. L. Hu, “Large spontaneous emission enhancement in plasmonic nanocavities,” Nat. Photonics6(7), 459–462 (2012).
[CrossRef]

L. Tang, S. E. Kocabas, S. Latif, A. K. Okyay, D.-S. Ly-Gagnon, K. C. Saraswat, and D. A. B. Miller, “Nanometre-scale germanium photodetector enhanced by a near-infrared dipole antenna,” Nat. Photonics2(4), 226–229 (2008).
[CrossRef]

L. Novotny and N. van Hulst, “Antennas for light,” Nat. Photonics5(2), 83–90 (2011).
[CrossRef]

W. A. Challener, C. Peng, A. V. Itagi, D. Karns, W. Peng, Y. Peng, X. Yang, X. Zhu, N. J. Gokemeijer, Y.-T. Hsia, G. Ju, R. E. Rottmayer, M. A. Seigler, and E. C. Gage, “Heat-assisted magnetic recording by a near-field transducer with efficient optical energy transfer,” Nat. Photonics3(4), 220–224 (2009).
[CrossRef]

Opt. Express

Phys. Rev. Lett.

T. Feichtner, O. Selig, M. Kiunke, and B. Hecht, “Evolutionary optimization of optical antennas,” Phys. Rev. Lett.109(12), 127701 (2012).
[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(9), 1667–1670 (1997).
[CrossRef]

P. J. Schuck, D. P. Fromm, A. Sundaramurthy, G. S. Kino, and W. E. Moerner, “Improving the mismatch between light and nanoscale objects with gold bowtie nanoantennas,” Phys. Rev. Lett.94(1), 017402 (2005).
[CrossRef] [PubMed]

Science

P. Mühlschlegel, H.-J. Eisler, O. J. F. Martin, B. Hecht, and D. W. Pohl, “Resonant optical antennas,” Science308(5728), 1607–1609 (2005).
[CrossRef] [PubMed]

S. Nie and S. R. Emory, “Probing single molecules and single nanoparticles by Surface-Enhanced Raman Scattering,” Science275(5303), 1102–1106 (1997).
[CrossRef] [PubMed]

Y. Fang, N.-H. Seong, and D. D. Dlott, “Measurement of the distribution of site enhancements in Surface-Enhanced Raman Scattering,” Science321(5887), 388–392 (2008).
[CrossRef] [PubMed]

Small

W. Zhu, M. G. Banaee, D. Wang, Y. Chu, and K. B. Crozier, “Lithographically fabricated optical antennas with gaps well below 10 nm,” Small7(13), 1761–1766 (2011).
[CrossRef] [PubMed]

T. S. van Zanten, M. J. Lopez-Bosque, and M. F. Garcia-Parajo, “Imaging individual proteins and nanodomains on intact cell membranes with a probe-based optical antenna,” Small6(2), 270–275 (2010).
[CrossRef] [PubMed]

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Figures (6)

Fig. 1
Fig. 1

Schematics of optical antenna designs. (a) Dipole antenna on ground plane for matched quality factors. (b) Patch antenna for sub-10 nm gap spacing. (c) Arch-dipole antenna for matched quality factors and sub-10 nm gap spacing.

Fig. 2
Fig. 2

Numerical simulations of gold patch antenna array. (a) Electric field profile of gold patch antenna. Patch antennas with dimensions of 50 nm square size, 25 nm thickness, and 5 nm Al2O3 gap were simulated with periodic boundary condition of 300 nm pitch. (b) Plot of calculated radiation and absorption quality factors as a function of gap spacing. (c) Plot of electric field enhancement as a function of gap spacing. Patch antenna arrays with various gap spacings (1, 2, 5, 10, and 20 nm) were simulated. Due to the growing mismatch between radiation and absorption quality factors, the increasing ratio of the field enhancement is suppressed as the gap is reduced below 2 nm.

Fig. 3
Fig. 3

Numerical simulations of gold arch-dipole antenna array. (a) Schematic of the simulated structure. 210 nm long, 50 nm wide, and 40 nm thick gold arch-dipole antennas with 5 nm gap and 30 nm arch height were simulated. Periodic boundary condition was used to calculate an antenna array with 600 nm pitch. (b) Electric field enhancement of arch-dipole antenna (red curve). Standard dipole antenna with same gap and length was also simulated for comparison (blue curve). Arch-dipole antenna has two modes depending on the current direction in the arch. (c) Electric field magnitude profile of simulated arch-dipole antennas. White arrows in antennas represent the current distribution. (d)-(f) Simulations of arch-dipole antennas with various arch heights. Field enhancement spectra show a maximum from arch-dipole antennas with 30 nm arch height (d). Quality factor (e) and field enhancement (f) were also plotted as a function of arch height. The field enhancement has a maximum peak at the optimum arch height for Q-matching condition (Qrad = Qabs).

Fig. 4
Fig. 4

Fabrication of the arch-dipole antennas. (a) Fabrication process of arch-dipole antenna. (b) SEM image of 5 nm Al2O3 nano-fins. The inset shows a perspective view of nano-fins. (c) SEM image of arch-dipole antenna array before etching Al2O3 fins. (d) Perspective view SEM image of arch-dipole antennas after etching Al2O3 fins. The inset shows the zoomed-in view of a representative single antenna.

Fig. 5
Fig. 5

Reflectance and SERS measurements of gold arch-dipole antenna array. (a) Reflectance measurement of arch-dipole antenna array with 210 nm length, 50 nm width, 40 nm thickness, 5 nm gap and 30 nm arch height. The reflectance spectrum confirms two antenna modes of arch-dipole antenna as expected in simulation. The inset shows the resonance shifts of higher frequency mode with antenna length variations. (b) Measured SERS spectra from trans-1,2-bis (4-pyridyl) ethylene (BPE) molecule. The strongest SERS signals were observed from antenna arrays (210 nm and 240 nm long antenna arrays) of which resonances were close to excitation laser wavelength (785 nm) and Stokes shifted wavelength (~870 nm). (c) SERS measurements with various angles of excitation polarization. Strong dependency on antenna resonance and excitation polarization is a clear evidence that SERS signals are resulted from optical antenna.

Fig. 6
Fig. 6

Comparison of measured SERS signals and calculated SERS enhancement factors from dipole antenna, patch antenna, and arch-dipole antenna. (a) SERS signals measured from different optical antenna designs. SERS spectra from dipole antenna array and patch antenna array were magnified by a factor of 10 for clarity. (b) Calculated SERS enhancement factors. Average enhancement factors were calculated assuming monolayer coating of BPE molecules on entire antenna surface. Hotspot enhancement factors were calculated from molecules coated on the sidewalls of antenna gap.

Equations (1)

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| E loc | 2 | E i | 2 = 2 A c λ res π Q Q rad Q V eff .

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