Enhanced Selective Field Ionization with Optical Dumping

Detection of Rydberg atoms by field ionization provides some degree of state identification due to the 1/$n^4$ scaling of the ionization threshold. However, some state information is lost when the atoms traverse avoided crossings during the ionization process. Here, we present an experimental method utilizing a ``dump pulse'' to detect dipole-dipole interactions involving initial and final states which would otherwise be indistinguishable in a field ionization signal.