Strong Raman enhancement in structured colloids: localization of light
Raman spectroscopy is a powerful technique for studying the interaction between light and matter. Here we show a significant enhancement of Raman emission over a broad range of pumping wavelengths from strongly scattering media comprising spatially correlated photonic structures of core–shell TiO 2 @Silica scatterers mixed with silica nanoparticles and suspended in ethanol. Long-range Coulomb interactions between nanoparticles inside these photonic colloidal structures induce a correlation in the scatterers’ positions (TiO 2 @Silica), affecting local and global photonic properties. The anomalous enhancement in Raman signal increases as the scattering strength is increased (through either scatterer concentration or pumping wavelength); however, the signal strength continues to behave linearly with excitation power, ruling out classical nonlinear and interferential phenomena. These observations may indicate strong photon correlation in strongly localized electromagnetic modes, inducing successive photon interactions with the atoms or molecules. Aside from the fundamental relevance to understanding measurable properties in this regime of strongly localized electromagnetic modes, our demonstration of strongly enhanced Raman emission over a broad range of pumping wavelengths provides new opportunities for the development of advanced photonic materials and devices.
Citação
@online{jessica2024,
author = {Jessica , Dipold and Niklaus U. , Wetter and Francisco C. ,
Marques and Anderson Z. , Freitas and Aristide , Dogariu and Ernesto
, Jiménez-Villar},
title = {Strong Raman enhancement in structured colloids: localization
of light},
volume = {41},
number = {6},
date = {2024-06-01},
doi = {10.1364/JOSAB.523100},
langid = {pt-BR},
abstract = {Raman spectroscopy is a powerful technique for studying
the interaction between light and matter. Here we show a significant
enhancement of Raman emission over a broad range of pumping
wavelengths from strongly scattering media comprising spatially
correlated photonic structures of core–shell TiO 2 @Silica
scatterers mixed with silica nanoparticles and suspended in ethanol.
Long-range Coulomb interactions between nanoparticles inside these
photonic colloidal structures induce a correlation in the
scatterers’ positions (TiO 2 @Silica), affecting local and global
photonic properties. The anomalous enhancement in Raman signal
increases as the scattering strength is increased (through either
scatterer concentration or pumping wavelength); however, the signal
strength continues to behave linearly with excitation power, ruling
out classical nonlinear and interferential phenomena. These
observations may indicate strong photon correlation in strongly
localized electromagnetic modes, inducing successive photon
interactions with the atoms or molecules. Aside from the fundamental
relevance to understanding measurable properties in this regime of
strongly localized electromagnetic modes, our demonstration of
strongly enhanced Raman emission over a broad range of pumping
wavelengths provides new opportunities for the development of
advanced photonic materials and devices.}
}