Absolute Te$_2$ reference for barium ion at $455.4~$nm

TL;DR

This paper introduces new tellurium lines for locking lasers at 455.4 nm to improve precision spectroscopy of barium ions, along with a wide-tuning ECDL, simplifying experimental setups in quantum tech and metrology.

Contribution

It provides new tellurium spectral lines for laser locking at 455.4 nm and develops a wide-tuning ECDL, enabling more stable and simplified barium ion spectroscopy.

Findings

New tellurium lines identified for 455.4 nm locking

ECDL with over 100 GHz tuning range developed

Reduced complexity in barium ion trap experiments

Abstract

Precision atomic spectroscopy is presently the work horse in quantum information technology, metrology, trace analysis and even for fundamental tests in physics. Stable lasers are inherent part of precision spectroscopy which in turn requires absolute wavelength markers suitably placed corresponding to the atomic species being probed. Here we present, new lines of tellurium (Te$_2$) which allows locking of external cavity diode laser (ECDL) for precision spectroscopy of singly charged barium ions. In addition, we have developed an ECDL with over 100 GHz mod-hop-free tuning range using commercially available diode from $\textit{Nichia}$. These two developments allow nearly drift-free operation of a barium ion trap set-up with one single reference cell thereby reducing the complexity of the experiment.