Laser-induced incandescence (2λ and 2C) for estimating absorption efficiency of differently matured soot

Abstract Two-wavelength and two-color laser-induced incandescence (2 λ –2C-LII) was used to study the absorption properties of three types cold soot different maturity from a mini-CAST generator. LII fluence curve analysis allowed for estimating wavelength dependence in terms dispersion coefficients ξ by use two excitation wavelengths (532 1064 nm). The estimated (based on E ( m, ) ∝ 1−ξ spanned ~ 1.2 mature soot, up 2.3 young soot. results showed good agreement with previous measurement using multi-wavelength extinction. For however, some discrepancy observed suggesting weaker (lower analysis. Furthermore, an estimation done experimental curves temperature low-fluence regime simulations model. Additionally, uncertainties limitations were discussed. Finally, it should be pointed out that caution has taken when interpreting 2 -LII obtain quantitative less which may influenced thermal annealing during laser pulse non-refractory species externally/internally mixed