Monolithic bowtie cavity traps for ultracold gases

Abstract

We report on trapping and cooling 6 Li 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.

Cavity-enhanced optical lattices for scaling neutral atom quantum technologies

“…We demonstrate the advantage of this flexibility by creating our lattices at an unconventional wavelength of 914.3 nm and show more than an order-of-magnitude improvement over free space setups based on the same lasers. While other cavity-enhanced lattices for similar purposes have been constructed in the past [24,27,28], our cavities have a factor of 3.5 larger mode area than the largest cavity-enhanced lattices [24], while achieving more than two orders of magnitude longer trap lifetime. Our cavity assembly is a monolithic device that contains two independent perpendicular optical cavities that cross at right angles, as shown in the photograph in Fig.…”

Crossed optical cavities with large mode diameters

“…In conclusion, we have demonstrated an optical assembly containing two perpendicular optical resonators with wellcrossed optical axes. Each resonator supports a fundamental mode with a 1/e 2 mode diameter of (910 µm) × λ/(914 nm), which results in an order-of-magnitude increase in available lattice sites compared to state-of-the-art free-space [9] and ringcavity-based [20], two-dimensional optical lattices. This compact optical assembly provides an optimal crossing of two separate laser beams, is compatible with operation in ultrahigh vacuum, has excellent mechanical and thermal stability, and enhances the optical power for multiple optical wavelengths of interest.…”