Fig. 1. Picture of laminar diffusion flame for propane-air

Fig. 2. Schematic of two-dimensional LIF-LII signal measurement experimental setup

Fig. 3. Schematic of time-resolved signal measurement experimental setup

Fig. 4. Two-dimensional distributions of soot-LII intensity at different wavelengths. (a) 450 nm; (b) 550 nm; (c) 650 nm

Fig. 5. Two-dimensional distributions of PAH-LIF and soot-LII intensity at different wavelengths. (a) 326 nm; (b) 365 nm; (c) 400 nm; (d) 450 nm; (e) 550 nm; (f) 600 nm

Fig. 6. Normalized intensity profiles along frame centerline obtained at different wavelengths versus frame height position

Fig. 7. Time-resolved signal peak intensity measured with PMT@450 nm versus frame height position under HE and LE conditions

Fig. 8. Time-resolved signal measured by PMT@405 nm at H_AB=25 mm and at H_AB=16mm, and single exponential decay fitted curve

Fig. 9. Normalized LIF time-resolved signal measured with PMT@450 nm at H_AB=22 mm under various laser fluence conditions

Fig. 10. Measured LIF decay times at different wavelengths as a function of frame height position and measured temperature in Ref.[25]