Generation of sub-ps IR pulses via parametric processes and application to transient spectroscopy of molecules

Intense pulses for two-color pump-probe spectroscopy in the mid-infrared spectral region are generated by subsequent parametric stages. Frequency down conversion yields pulses from 2.6 to 7 μm with a duration of 0.5 ps, while 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 solution of HDO in heavy water yields significant vibrational lifetime shortening for the OH-mode from 1 ps at 298 K down to 0.5 ps at 268 K for hexagonal ice.