Efficient and robust photo-ionization loading of beryllium ions

TL;DR

This paper presents a highly efficient photo-ionization method for loading beryllium ions using a short, high-energy laser pulse at 235 nm, significantly improving ion loading efficiency in a linear Paul trap.

Contribution

The authors introduce a novel two-step photo-ionization technique with a short laser pulse that achieves over 15 times higher efficiency than previous methods.

Findings

Achieved ion loading with a 60 ns, 150 nJ laser pulse at 235 nm.

Demonstrated over 15-fold increase in efficiency compared to previous two-photon methods.

Effective saturation of the atomic velocity distribution with a resonant step.

Abstract

We demonstrate the efficient generation of Be$^+$ ions with a 60 ns and 150 nJ laser pulse near 235 nm for two-step photo-ionization, proven by subsequent counting the number of ions loaded into a linear Paul trap. The bandwidth and power of the laser pulse are chosen in such a way that a first, resonant step fully saturates the entire velocity distribution of beryllium atoms effusing from a thermal oven. The second excitation step is driven by the same light field causing efficient non-resonant ionization. Our ion-loading scheme is more than 15 times more efficient as compared to former pathways using two-photon continuous wave laser excitation.