Surface-enhanced hyper-Raman spectra and enhancement factors for three SERS chromophores. SEHRS spectra on Ag films at pulse energies below 2 pJ.
Hyper-Raman scattering, the nonlinear (two-photon excited) analogue of ordinary Raman scattering, is usually considered to be a weak process that requires high-energy pulsed laser excitation. The sensitivity can be improved greatly by making use of two-photon electronic resonance and/or electromagnetic field enhancement on metal nanoparticle surfaces. Here we demonstrate that hyper-Raman spectra can be obtained from organic dyes on silver colloidal nanoparticle films at laser powers below 1 mW of average power (pulse energies below 2 pJ). These results open the door to exploiting the potential advantages of hyper-Raman scattering for analytical applications.
Leng
Weinan
W
School of Natural Sciences, University of California, Merced, P.O. Box 2039, Merced, California 95344, USA.
Kelley
Anne Myers
AM
D002232:Carbocyanines / Q000737:chemistry*; D003102:Colloids; D005456:Fluorescent Dyes / Q000737:chemistry; D005840:Gentian Violet / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry*; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*
D002232:Carbocyanines; D003102:Colloids; D005456:Fluorescent Dyes; D012235:Rhodamines; C026188:rhodamine 6G; D012834:Silver; D005840:Gentian Violet