Building electronic wave packets from scratch

Summary form only given. Unipolar half-cycle pulses (HCPs) can be used to alter the momentum distribution of atomic electrons over subpicosecond timescales. Previously, momentum kicks from HCPs were used to produce electronic wave packets from highly excited Rydberg eigenstates. In addition, these pulses have been used to kick bound electrons into the continuum, making it possible to monitor the time-dependent momentum distribution of electronic wave packets. Conversely, our most recent experiments have shown that HCPs can extract momentum from free electrons, facilitating their capture by positive ions. In the experiments, calcium atoms in the singlet 4s4p level are photoionized into the continuum using a 1.5ps, 390-nm laser pulse.