Experimental comparison of Raman and RF outcouplers for high flux atom lasers

TL;DR

This paper compares three outcouplers for atom lasers derived from Bose-Einstein condensates, highlighting that a two-state Raman outcoupler offers the best performance for high flux, low divergence beams, with implications for interferometry.

Contribution

It provides an experimental comparison of Raman and RF outcouplers, identifying the two-state Raman outcoupler as optimal for high flux atom lasers.

Findings

Two-state Raman outcoupler yields higher flux

Bound states limit atom laser flux in all outcouplers

Two-state Raman outcoupler produces low divergence beams

Abstract

We study the properties of an atom laser beam derived from a Bose-Einstein condensate using three different outcouplers, one based on multi-state radio frequency transitions and two others based on Raman transitions capable of imparting momentum to the beam. We first summarize the differences that arise in such systems, and how they may impact on the use of an atom laser in interferometry. Experimentally, we examine the formation of a bound state in all three outcouplers, a phenomenon which limits the atom laser flux, and find that a two-state Raman outcoupler is the preferred option for high flux, low divergence atom laser beams.