R. Laenen et al., Generation of sub-ps IR pulses via parametric processes and application totransient spectroscopy of molecules, LASER PHYS, 9(1), 1999, pp. 234-238
Intense pulses for two-color pump-probe spectroscopy in the mid-infrared sp
ectral region are generated by subsequent parametric stages. Frequency down
conversion yields pulses from 2.6 to 7 mu m with a duration of 0.5 ps, whi
le independent adjustment of the pulse duration is achieved from 0.5 to 2.6
ps. Application of these pulses to transient spectroscopy of a 0.8 M solut
ion of HDO in heavy water yields significant vibrational lifetime shortenin
g for the OH-mode from 1 ps at 298 K down to 0.5 ps at 268 K for hexagonal
ice.