Figure 5.

Deconvolution of spectral overlapping, exemplified for the determination of exact T₂/DT concentrations in the KNM1 gas mixture. Top-left—segment of the spectrum in Figure 3c (the scale is split, to visualize all spectral features; center-left—theoretical O₁(J″)/S₁(J″) lines for T₂, overlaid on the experimental spectrum, with the individual Raman lines annotated; bottom-left—spectrum with the O₁(J″)/S₁(J″) lines subtracted, leaving only the Q₁(J″)-branches to evaluate species concentrations. Top-right—experimental line profile function, derived using ShapeFit; center-right—theoretical Raman line strengths φij for the O₁(J″)/Q₁(J″)/S₁(J″) lines of T₂ and DT, calculated for a gas temperature of T = 298 ± 2 K. Note that the values for the O₁(J″)/S₁(J″) lines of T₂ are scaled by ×20, to emphasize the overlap between T₂ S₁(2) and DT Q₁(J”).