On the dynamics of rotationally broad, spatially aligned wave packets

The problems of rotational excitation and molecular alignment in moderately intense laser fields are addressed theoretically and numerically. Several scaling propensities are derived, which connect the achievable alignment with the underlying field and molecular parameters. An analytical model is developed, which exposes the origin of alignment in the short-pulse limit. A numerical study is presented, which quantifies the notions of adiabatic and sudden alignment and illustrates the behavior of the post-pulse alignment subsequent to slow turn-on and rapid turn-off of the laser pulse. Several new potential applications of laser alignment are proposed. (C) 2001 American Institute of Physics.