Design and assembly of a cavity microscope with high numerical aperture for quantum simulations

TL;DR

This paper details the design and assembly of a high-numerical aperture cavity microscope optimized for quantum simulations with ultracold atoms, combining high finesse and broad optical access.

Contribution

It introduces a novel cavity microscope design that integrates a high-finesse optical cavity with high-NA lenses in a rigid structure, enhancing atomic manipulation and imaging capabilities.

Findings

Cavity length of 19.786 mm with finesse of 2.35×10^4

Numerical aperture of 0.52 for each lens

Operates deep in the strong coupling regime near the concentric limit

Abstract

We present the design and assembly of a cavity microscope for quantum simulations with ultracold atoms. The system integrates a high-finesse optical cavity with a pair of high-numerical aperture lenses sharing a common optical axis, enabling simultaneous operation with light close-to-atomic resonance. The system keeps the advantages of a rigid, single-block structure holding the lenses and cavity together, and improves over existing designs by using most of the solid angle left free by the cavity mode for imaging and atomic manipulation purposes. The cavity has a length of \SI{19.786}{\milli\meter}, a finesse of \SI{2.35}{\times 10^4} and operates \SI{214}{\micro\meter} away from the concentric limit, deep in the strong coupling regime. The two lenses offer a numerical aperture of $0.52$ each and maximal optical access in all directions transverse to the cavity axis, compatible with applications in quantum-gas microscopes, micro-tweezer arrays or few-fermions systems, as well as future cavity-assisted quantum simulation protocols demanding sub-cavity-mode control of the atom-cavity coupling.