  We report attosecond-scale probing of the laser-induced dynamics in
molecules. We apply the method of high-harmonic spectroscopy, where
laser-driven recolliding electrons on various trajec- tories record the motion
of their parent ion. Based on the transient phase-matching mechanism of
high-order harmonic generation, short and long trajectories contributing to the
same harmonic order are distinguishable in both the spatial and frequency
domains, giving rise to a one-to-one map between time and photon energy for
each trajectory. The short and long trajectories in H2 and D2 are used
simultaneously to retrieve the nuclear dynamics on the attosecond and angstrom
scale. Compared to using only short trajectories, this extends the temporal
range of the measurement to one optical cycle. The experiment is also applied
to methane and ammonia molecules.
