Wave packet dynamics

Wave packets (WP) result from the coherent superposition of two or more eigenstates in atoms or molecules and can be generated with pulsed lasers which are spectrally broad and temporary short. One of the methods in ultrafast measurements for creating WPs is Four-wave mixing (FWM)

   FWM is implemented in folded box cars geometry where three beams are focused into the sample. By nonlinear interaction with atoms the fourth beam is generated which represents the signal.
    Temporal resolution is achieved in transient grating arrangement, i.e. the first two beams come simultaneously and the third beam is delayed in time by translational stage.
    The signal at negative times shows dynamics of the excited states while the signal at positive times can be both from the excited and ground states.    Next Page