Monolithic bowtie cavity traps for ultra-cold gases

TL;DR

This paper demonstrates a monolithic ring bowtie cavity for trapping and cooling Li-6 atoms, featuring magnetic insensitivity and long trap lifetimes suitable for quantum gas experiments.

Contribution

It introduces a monolithic fused silica and Zerodur cavity with hydroxide bonding, enabling stable ultra-cold atom trapping with minimized magnetic sensitivity.

Findings

Successful trapping and cooling of Li-6 atoms.

Long trap lifetimes achieved with phase-controlled bi-directional pumping.

Cavity construction compatible with ultra-high vacuum conditions.

Abstract

We report on trapping and cooling Li-6 atoms in a monolithic ring bowtie cavity. To make the cavity insensitive to magnetic fields used to tune atomic interactions, we constructed it entirely from fused silica and Zerodur. The components were assembled using hydroxide bonding, which we show can be compatible with ultra-high vacuum. Backscattering in high-finesse ring cavities readily causes trap intensity fluctuations and heating, but with phase-controlled bi-directional pumping the trap lifetime can be made long enough for quantum gas experiments in both the crossed-beam trap (unidirectional pump) and 2D lattice trap (bidirectional pump) configurations.