Subtraction procedure used to produce time-resolved Raman spectra of β-carotene. The pump + probe spectrum (A) with Δt = 6 ps, pump-only spectrum (B, dashed), and toluene probe-only spectrum (D) were collected under the conditions described in the text. The pump induced fluorescence (B) is subtracted from the pump + probe spectrum (A) and corrected for β-carotene self-absorption by dividing by T(λ), the β-carotene transmission spectrum. The toluene peaks in this spectrum (C) are removed by subtracting the toluene probe-only spectrum (D). The resultant spectrum (E) contains both β-carotene Raman scattering and residual fluorescence. The fluorescence background is fit (F, dotted) and subtracted to give the background free pump + probe Raman spectrum of β-carotene (G). The anti-Stokes region of spectrum G has been magnified ×4 for display.