Producing translationally cold, ground-state CO molecules

TL;DR

This paper demonstrates a method to produce translationally cold, ground-state CO molecules suitable for trapping experiments by combining Stark deceleration and optical transfer techniques, with experimental validation of the transfer scheme.

Contribution

It introduces a novel approach to generate cold CO molecules in the ground state through Stark deceleration and optical transfer, with experimental confirmation of the process.

Findings

Optical transfer scheme successfully demonstrated.

Radiative lifetimes and dipole moments measured.

Cold CO molecules suitable for trapping produced.

Abstract

Carbon monoxide molecules in their electronic, vibrational, and rotational ground state are highly attractive for trapping experiments. The optical or ac electric traps that can be envisioned for these molecules will be very shallow, however, with depths in the sub-milliKelvin range. Here we outline that the required samples of translationally cold CO (X$^1\Sigma^+$, $v"$=0, $N"$=0) molecules can be produced after Stark deceleration of a beam of laser-prepared metastable CO (a$^3\Pi_1$) molecules followed by optical transfer of the metastable species to the ground state \emph{via} perturbed levels in the A$^1\Pi$ state. The optical transfer scheme is experimentally demonstrated and the radiative lifetimes and the electric dipole moments of the intermediate levels are determined.