Fig. 1. (A) Spectrogram of the CS₂/benzene mixture with three regions of interest (R1, R2, and R3) highlighted. R1 shows the resonant response from the CS₂ 656 cm⁻¹ peak, while R2 shows the resonant response of the 991 cm⁻¹ benzene peak. R3 highlights the instrument response function, used to measure the temporal profile of the probe pulse. (B) The instrument response as measured from a lineout in region R3, with a Gaussian fit to the central maximum, with full-width-at-half-maximum (FWHM) of 265 fs.

Fig. 2. (A) A lineout from the spectrogram in Figure 1A taken at the 656 cm⁻¹ CS₂ peak. (B) A lineout from the spectrogram in Figure 1A taken at the 991 cm⁻¹ benzene peak. In both figures the data was fitted with an exponential decay function (pink line) from 400 fs onwards.

Fig. 3. (A) The spectrogram of the CS₂/benzene mixture obtained by targeting different wavenumbers using quadratic phase spectral focussing and a probe delayed by 800 fs with respect to the pump. (B) The lineouts at 656 cm⁻¹ and 991 cm⁻¹ target wavenumbers, indicating the suppression of the non-resonant background.