Ultra-low-loss nanofiber Fabry-P\'erot cavities optimized for cavity quantum electrodynamics

TL;DR

This paper reports the fabrication of ultra-low-loss nanofiber Fabry-Pérot cavities with high finesse and cooperativity, optimized for cavity quantum electrodynamics, enabling advancements in scalable quantum networks.

Contribution

The authors demonstrate a precise fabrication method for ultra-low-loss nanofiber cavities with high finesse and cooperativity, suitable for quantum information applications.

Findings

Internal round-trip loss of 0.31% at 207 nm radius

Total finesse of 1380 achieved

Maximum internal cooperativity of ~1050 for cesium atoms

Abstract

We demonstrate the fabrication of ultra-low-loss, all-fiber Fabry-P\'erot cavities containing a nanofiber section, optimized for cavity quantum electrodynamics. By continuously monitoring the finesse and fiber radius during fabrication of a nanofiber between two fiber Bragg gratings, we are able to precisely evaluate taper transmission as a function of radius. The resulting cavities have an internal round-trip loss of only 0.31% at a nanofiber waist radius of 207 nm, with a total finesse of 1380, and a maximum expected internal cooperativity of $\sim$ 1050 for a cesium atom on the nanofiber surface. Our ability to fabricate such high-finesse nanofiber cavities may open the door for the realization of high-fidelity scalable quantum networks.