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 ${{\rm TiO}_2}@{\rm Silica}$ 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 (${{\rm TiO}_2}@{\rm Silica}$), 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.

© 2024 Optica Publishing Group

Ordered photonic colloidal suspensions

Ernesto Jiménez-Villar, Weliton S. Martins, and Niklaus U. Wetter
Appl. Opt. 62(11) 2707-2710 (2023)

Broadband and high-enhancement-factor integrated long-wave infrared sensor using the photonic crystal assisted subwavelength grating waveguide

Dong Zhang, Jie Liao, Pengjun Wang, Qiang Fu, Weiwei Chen, Shixun Dai, LiPeng Deng, Jun Li, Tingge Dai, and Jianyi Yang
J. Opt. Soc. Am. B 41(5) 1170-1179 (2024)

Anomalous transport of light at the phase transition to localization: strong dependence with incident angle

Ernesto Jimenez-Villar, M. C. S. Xavier, Niklaus U. Wetter, Valdeci Mestre, Weliton S. Martins, Gabriel F. Basso, V. A. Ermakov, F. C. Marques, and Gilberto F. de Sá
Photon. Res. 6(10) 929-942 (2018)

Adjoint-based optimization of dielectric coatings for refractory metals to achieve broadband spectral reflection

Amin Balazadeh Koucheh, Muhammed Ali Kecebas, and Kursat Sendur
J. Opt. Soc. Am. B 41(2) A98-A107 (2024)

Role of gas nanobubbles in nonlinear hyper-Raman scattering of light in water

V. A. Babenko, N. F. Bunkin, and A. A. Sychev
J. Opt. Soc. Am. B 37(9) 2805-2814 (2020)