Selective Strong-Field Enhancement and Suppression of Ionization with Short Laser Pulses

TL;DR

This paper demonstrates how intense short laser pulses can selectively enhance or suppress ionization of atomic Rydberg states in sodium vapor, revealing a new method of controlling atomic populations via strong field effects.

Contribution

It introduces a novel experimental approach for coherent control of atomic states using strong laser fields, emphasizing the role of Freeman resonance in this process.

Findings

Selective excitation and attenuation of Rydberg states achieved

Control demonstrated at intensities above over-the-barrier ionization

Qualitative model supports the role of Freeman resonance

Abstract

We experimentally demonstrate robust selective excitation and attenuation of atomic Rydberg level populations in sodium vapor (Na I) using intense laser pulses in the strong field limit ($> 10^{12} W/cm^{2}$). The coherent control of the atomic population and related ionization channels is realized for intensities above the over-the-barrier ionization intensity. A qualitative model predicts that this strong field coherent control arises through the manifestation of a Freeman resonance.