Ultra-rapid-scanning spectrometer

Since modern FTIR spectrometers can operate in a rapid scan mode with approximately 50 ms time resolution, TRIR experiments in the millisecond time regime are readily available. Recent advances in ultra-rapid scanning FTIR spectroscopy have improved the obtainable time resolution to 5 ms. Alternatively, experiments can be performed at time resolutions on the order of 1-10 ms with the planar array IR technique, which utilizes a spectrograph for wavelength dispersion and an IR focal plane detector for simultaneous detection of multiple wavelengths. ... 

Transient absorption spectroscopy, wherein one measures the electronic absorption spectrum of a molecule in an excited state, is still in its infancy, but the growing availability of ultra-high-speed, rapid-scan spectrometers augurs well for this area of spectroscopy. Thus one may, in the future, routinely probe excited state absorption spectra as well as ground state absorption spectra. The former can be expected to be as valuable in obtaining information about the excited state as is the latter for the ground state. 

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