Femtosecond real-time pump–probe imaging spectroscopy

Real-time pump–probe imaging spectroscopy with femtosecond time resolution is demonstrated. This method allows real-time mapping of frequency- and time-resolved transient absorption of materials at once. We can clearly measure the image of the transient absorption spectra of β-carotene with wide temporal and spectral ranges in a short accumulation time. Since the typical accumulation time is about two orders of magnitude shorter than that by the conventional pump–probe technique, this method becomes a powerful spectroscopic tool to study ultrafast relaxation and dynamics on organic/biochemical materials, which easily undergo photofatigue after many repetitions of the pump–probe sequence.