A high-flux, adjustable, compact cold-atom source

Abstract

Magneto-optical traps (MOTs) are widely used for laser cooling of atoms. We have developed a high-flux compact cold-atom source based on a pyramid MOT with a unique adjustable aperture that is highly suitable for portable quantum technology devices, including space-based experiments. The adjustability enabled an investigation into the previously unexplored impact of aperture size on the atomic flux, and optimisation of the aperture size allowed us to demonstrate a higher flux than any reported cold-atom sources that use a pyramid, LVIS, 3D-MOT or grating MOT. We achieved 2.0(1) × 10 10 atoms/s of 87 Rb with a mean velocity of 32(1) m/s, FWHM of 27.6(9) m/s and divergence of 58(3) mrad. Halving the total optical power to 195 mW caused only a 26% reduction of the flux, and a 33% decrease in mean velocity. Methods to further decrease the velocity as required have been identified. The low power consumption and small size make this design suitable for a wide range of cold-atom technologies.