Quantum-beat Spectroscopy of Molecular Dynamics in Ultrashort Laser Fields

Reaction Microscope-based, complete, and time-resolved Coulomb explosion imaging of vibrating and dissociating $D_2^+$ molecules with femtosecond time-resolution allowed us to perform an internuclear distance (R-)dependent Fourier analysis of the corresponding wave packets. Our wave packet propagation calculations demonstrate that the obtained two-dimensional R-dependent frequency spectra enable the complete characterization of the wave packet dynamics and directly visualize the field-modified molecular potential curves in intense, ultrashort laser pulses, cf., Phys. Rev. Lett. {\bf 99} 153002 (2007) and Phys. Rev. A {\bf 77}, 063401 (2008).