All-Optical Realization of an Atom Laser

TL;DR

This paper reports the all-optical creation and extraction of a Bose-Einstein condensate of rubidium atoms, producing a continuous, monoenergetic atom laser beam with suppressed magnetic field fluctuations.

Contribution

It introduces a novel all-optical method for generating an atom laser using a single CO$_{2}$-laser beam and magnetic field control to enhance stability.

Findings

Successful creation of a rubidium Bose-Einstein condensate in a quasistatic dipole trap.

Continuous extraction of a monoenergetic atom laser beam.

Suppression of chemical potential fluctuations via magnetic field gradient control.

Abstract

We demonstrate an atom laser using all-optical techniques. A Bose-Einstein condensate of rubidium atoms is created by direct evaporative cooling in a quasistatic dipole trap realized with a single, tightly focused CO$_{2}$-laser beam. An applied magnetic field gradient allows formation of the condensate in a field-insensitive $m_{F} = 0$ spin projection only, which suppresses fluctuations of the chemical potential from stray magnetic fields. A collimated and monoenergetic beam of atoms is extracted from the Bose-Einstein condensate by continuously lowering the dipole trapping potential in a controlled way to form a novel type of atom laser.