Generation of frequency shifted picosecond pulses with low temporal jitter

Transient stimulated Raman scattering is used for the generation of
a frequency shifted picosecond light pulse; part of this Raman
shifted pulse is subsequently coherently scattered at a material
excitation of a second Raman cell. Starting with the second
harmonic pulse (tp = 4 ps) of a mode-locked Nd : glass laser
system, both the stimulated and the coherently produced pulses have
durations of 2.3 ps at different wavelengths. By the appropriate
choice of the Raman medium pulses between 13 000 and 21 000 cm-1
can be generated. The coherent generation process minimizes the
temporal jitter between the two pulses and allows to obtain a high
time resolution of better than 0.3 ps in excite and probe
experiments.