Characterization of quasi-one-dimensional Rydberg atoms using multiply directed half-cycle pulses

Abstract

The characteristics of quasi-one-dimensional (1D) high-$n$ Rydberg atoms produced by photoexciting, in a weak dc field, extreme members of the $n=350$ Stark manifold are investigated by studying their ionization when subjected to unidirectional electric field pulses, termed half-cycle pulses (HCP's), of duration ${T}_{p}⪡{T}_{n}$ where ${T}_{n}$ is the classical electron orbital period, directed both parallel and perpendicular to the atomic axis. The observed differences in the ionization characteristics provide a measure of the anisotropy of the momentum distribution. It is shown that HCP's applied transverse to the atomic axis provide a particularly sensitive probe of the quasi-1D nature of the state. The experimental data are in good agreement with the results of classical trajectory Monte Carlo simulations.