Cold Atomic Sensors with Millimeter Resolution Using Hollow-Core Fibers

Atom interferometers integrated within hollow-core fibers enable precise positioning of atoms near a target field source, enhancing signal detection while achieving high spatial resolution. In this work, we propose the development of a compact, standalone device featuring a meter-long tubular ring hollow-core fiber positioned outside a stainless-steel vacuum enclosure. To simplify the traditional complex setup of a magneto-optical trap (MOT), we will employ an axicon mirror combined with a single laser beam. This design will not only streamline the adjustment of the atom loading position relative to the fiber but also reduce the length of the fiber required within the stainless-steel chamber. Furthermore, we plan to phase-lock co-propagating cooling and repumping beams to implement Λ-enhanced gray molasses cooling, improving atom temperature and density, thereby significantly enhancing loading efficiency.