Jm. Funk et al., Nanosecond time-resolved resonance CARS spectroscopy using the scanning multichannel technique, APPL SPECTR, 52(12), 1998, pp. 1541-1553
We report on an experimental setup which has been developed to perform effi
cient nanosecond time-resolved coherent anti-Stokes Raman scattering (CARS)
experiments using either the scanning CARS or the broadband CARS technique
. A special electronic device has been constructed that allows the CARS pro
bing laser system to be triggered with a variable delay after the excitatio
n pulse of a nitrogen laser and furthermore prevents any temporal drifts of
the nitrogen laser emission. The acquisition of the broadband CARS spectra
is based on the recently developed scanning multichannel technique, which
is applied in the present paper to CARS spectroscopy. Several examples of g
round- and excited-state CARS spectra are shown to demonstrate the performa
nce of the setup and to point out the benefits and limitations of the vario
us measurement techniques. Moreover, we present CARS spectroscopic investig
ations of triplet relaxation processes in order to illustrate the feasibili
ty of the designed spectrometer for nanosecond time-resolved CARS experimen
ts.