Continuous-Wave Coherent Raman Spectroscopy via Plasmonic Enhancement

Sci Rep. 2019 Aug 20;9(1):12092. doi: 10.1038/s41598-019-48573-8.


In this paper, we report a successful combination of stimulated Raman spectroscopy (SRS) and surface-enhanced Raman scattering (SERS) using cw laser sources and gold/silica nanoparticles with embedded reporter molecules. We describe the preparation method for our gold/silica nanoparticles as well as the effect of probe wavelength, pump and probe power, polarization and sample concentration on the cwSESRS signal. Altogether, a stable ~12 orders of magnitude enhancement in the stimulated Raman signal is achieved because of the amplification of both pump and probe beams, leading to the detection of pico-molar nanoparticle concentrations, comparable to those of SERS. The coherent Raman spectra matches the incoherent conventional Raman spectra of the reporter molecules. Unlike conventional incoherent SERS this approach generates a coherent stimulated signal of microwatt intensities, opening the field to applications requiring a coherent beam, such as Molecular Holography.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gold / chemistry
  • Lasers*
  • Longitudinal Studies
  • Metal Nanoparticles / chemistry*
  • Silicon Dioxide / chemistry*
  • Spectrum Analysis, Raman / methods*


  • Gold
  • Silicon Dioxide