Multicolor-Raman analysis of Korean paintworks: emission-like Raman collection efficiency

It has been reported that the scattering cross-sections of resonance Raman spectra strongly depend on the resonance between the laser's excitation energy and the electronic absorption band of pigments in solution. However, the actual collection of scattered photons is affected by diffuse scattering and self-absorption when studying painted colorants in artworks. Quantitative spectroscopic measurements are required to elucidate the apparent resonance Raman cross-sections in both solution and solid. In this study, we explored the excitation-dependent Raman scattering of natural and artificial Korean pigments painted on a wood block with six visible wavelengths. Our study shows that the Raman intensity profile agrees with the emission profile rather than with the absorption. We also assessed the validity of self-absorption and the outgoing resonance mechanism in the solid state for the results.