Fig. 3: 1.25-Gfps LS-CUP imaging of one-color laser-induced incandescence (LII) of soot particles and primary soot particle size distributions determined by time-resolved LII.

Reconstructed spatiotemporal dynamics of one-color LII signals: a and b at height h2; c and d at height h1; a and c 3D representations of the full sequence; b and d selected snapshots. Scale bars in (b) and (d): 2 mm. Soot particle size distributions in the x-y plane at heights (e) h2 and (f) h1. g Soot particle size distributions along the x direction, at vertical locations y1 to y7, indicated by the short lines in (e) and (f). Average soot particle size along the vertical direction at height (h) h2 and (i) h1