Stimulated Raman Adiabatic Passage for Improved Performance of a Cold Atom Electron and Ion Source

TL;DR

This paper demonstrates that using stimulated Raman adiabatic passage significantly enhances the efficiency of exciting Rydberg states in a cold atom electron and ion source, leading to brighter and faster particle bunches for advanced imaging.

Contribution

It introduces a high-efficiency coherent excitation method via stimulated Raman adiabatic passage for cold atom electron and ion sources, surpassing previous incoherent excitation techniques.

Findings

Achieved 60% average excitation efficiency, peak 82%.

Produced electron bunches with 250 ps duration.

Enhanced source brightness for ultrafast electron diffraction.

Abstract

We implement high-efficiency coherent excitation to a Rydberg state using stimulated Raman adiabatic passage in a cold atom electron and ion source. We achieve an efficiency of 60% averaged over the laser excitation volume with a peak efficiency of 82%, a 1.6 times improvement relative to incoherent pulsed-laser excitation. Using pulsed electric field ionization of the Rydberg atoms we create electron bunches with durations of 250 ps. High-efficiency excitation will increase source brightness, crucial for ultrafast electron diffraction experiments, and coherent excitation to high-lying Rydberg states could allow for the reduction of internal bunch heating and the creation of a high-speed single ion source.