Postprint version. Published in Physical Review A, Volume 51, Issue 4, April 1, 1995, pages 3370-3373.
NOTE: At the time of publication, the author Thomas Bensky was not yet affiliated with Cal Poly.
The definitive version is available at https://doi.org/10.1103/PhysRevA.51.3370.
Rydberg atoms are ionized by nearly unipolar, subpicosecond electromagnetic pulses. Deviations from a perfectly unidirectional pulse are found to alter substantially the ionization probability as a function of peak field. Quantitative agreement between classical theory and experiment is achieved if the pulse imperfections are significantly attenuated.