Title: Femtosecond Laser Control of the Angular Distribution of Electrons Due to Autoionization

M.L. Bajema, R.R. Jones, and T.F. Gallagher

Abstract:

Using two 500 fsec laser pulses and a controlled time delay between them we are able to manipulate the angular distributions of the electrons ejected by autoionization of Ca atoms in the 4p_3/221s and 4p_3/219d states. Subsequent to their isolated core excitation by a 500 fsec 393 laser pulse, Ca 4p_3/221s(19d) Rydberg atoms coherently evolve, via configuration interaction, into the degenerate 4p_1/2ns(nd) states. While in the 4p_1/2ns(nd) states, atoms can be de-excited to bound 4sns(nd) levels using a 500 fsec 397nm pulse. Removing these atoms from the autoionizing states leads to a greater fraction of electrons leaving the atom along the direction of the laser polarization than is possible through direct excitation of 4p_3/2ns(nd) or 4p_1/2ns(nd) using either the 393nm or 397nm pulse alone.

Status: Published Physical Review A 70, 062722 (2004).