Hollow Bessel beams for guiding atoms between vacuum chambers: A proposal and efficiency study

TL;DR

This paper proposes using hollow Bessel beams generated by simple optical components to efficiently guide cold atoms between vacuum chambers, analyzing beam profiles, diffraction effects, and atom transfer efficiency through simulations.

Contribution

It introduces a practical scheme for atom guiding with hollow Bessel beams, including analytical expressions and efficiency analysis, advancing atom transfer techniques between chambers.

Findings

Bessel beam profiles match numerical simulations.

Diffraction effects influence beam propagation.

Enhanced atom transfer efficiency with intense Bessel beams.

Abstract

We explore a scheme for guiding cold atoms through a hollow Bessel beam generated by a single axicon and a lens from a 2D magneto-optical trap toward a science chamber. We compare the Bessel beam profiles measured along the optical axis to a numerical propagation of the beam's wavefront, and we show how it is affected by diffraction during the passage through a long narrow funnel serving as a differential pumping tube between the chambers. We derive an approximate analytic expression for the intensity distribution of the Bessel beam and the dipolar optical force acting on the atoms. By a Monte-Carlo simulation based on a stochastic Runge-Kutta algorithm of the motion of atoms initially prepared at a given temperature we show that a considerable enhancement of the transfer efficiency can be expected in the presence of a sufficiently intense Bessel beam.