Extending a continuous scan Fourier transform spectrometer for time-resolved Fourier transform spectroscopy with <0.5 cm−1 spectral and <10 ns time resolution in the visible region

The extension of a continuous scan high spectral resolution (0.006 cm−1) Fourier transform spectrometer for time-resolved Fourier transform spectroscopy with a temporal resolution in the ns regime is described. The time resolution is achieved by synchronizing a laser/transient digitizer system with the interferometer. The realization of the data acquisition and the experimental setup are described. Examples of time-resolved measurements are given. Detector limited temporal resolution of <10 ns is shown by recording scattered light from a pulsed dye laser. Spectral resolution of <0.5 cm−1 is demonstrated by observing the fluorescence of electronically excited CH radicals produced in the multi photon dissociation of CHBr3. The signal-to-noise behavior of time-resolved Fourier transform apparatus is investigated as a function of spectral (0.1–4.0 cm−1 unapodized) and time resolution and of the intensity of the detected light.