Selective Coherent Anti-Stokes Raman Scattering Microscopy Employing Dual-Wavelength Nanofocused Ultrafast Plasmon Pulses

Keita Tomita, Yasuhiro Kojima, Fumihiko Kannari

Research output: Contribution to journalArticle

11 Citations (Scopus)

Abstract

Ultrafast surface plasmon polariton (SPP) nanofocusing on a plasmonic metal tapered tip with femtosecond laser pulses enables background-free localized excitation beyond the diffraction limit. We demonstrate simultaneous nanofocusing of ultrafast SPP pulses at 440 and 800 nm, which were coupled with a common diffraction grating structure fabricated on an aluminum (Al) tapered tip, to the tip apex with a radius of ?35 nm. We achieved selective coherent anti-Stokes Raman scattering (CARS) microscopy that combined an 800 nm (ω) SPP pump pulse, which achieves selective vibrational excitation by spectral focusing, and a 440 nm (2ω) SPP probe pulse. Raman intensity of this novel 2ω-CARS increased by a factor of 3.96 at the G-band and 4.00 at the 2D-band compared with that with ω-CARS for the monolayer graphene. The 2ω-CARS imaging method was applied for imaging a multiwalled carbon nanotube at the D-, G-, and 2D-bands. This dual-wavelength nanofocusing will open up new nanoscale microspectroscopy and optical excitation at the tip apex, such as sum frequency mixing, two-photon excitation.

Original languageEnglish
Pages (from-to)1366-1372
Number of pages7
JournalNano Letters
Volume18
Issue number2
DOIs
Publication statusPublished - 2018 Feb 14

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Keywords

  • coherent anti-Stokes Raman scattering
  • nanofocusing
  • nonlinear microscopy
  • pulse shaping
  • Surface plasmon polaritons

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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