Efficient photoionization for barium ion trapping using a dipole-allowed resonant two-photon transition

TL;DR

This paper demonstrates a highly efficient, isotope-selective photoionization method for barium ions using a resonant two-photon transition at 553 nm, outperforming previous techniques and suitable for commercial laser systems.

Contribution

Introduces a new photoionization scheme at 553 nm that significantly improves efficiency and isotope selectivity for barium ion trapping.

Findings

Two orders of magnitude increase in ionization efficiency.

The method is compatible with commercial laser systems.

It offers advantages over existing narrowband photoionization schemes.

Abstract

Two efficient and isotope-selective resonant two-photon ionization techniques for loading barium ions into radio-frequency (RF)-traps are demonstrated. The scheme of using a strong dipole-allowed transition at \lambda=553 nm as a first step towards ionization is compared to the established technique of using a weak intercombination line (\lambda=413 nm). An increase of two orders of magnitude in the ionization efficiency is found favoring the transition at 553 nm. This technique can be implemented using commercial all-solid-state laser systems and is expected to be advantageous compared to other narrowband photoionization schemes of barium in cases where highest efficiency and isotope-selectivity are required.