Collimated versatile atomic beam source with alkali dispensers

TL;DR

This paper introduces a compact, integrated rubidium dispenser with a collimator that produces a directed atomic beam at a lower temperature, suitable for on-chip quantum applications.

Contribution

The authors develop a novel, thin dispenser collimator device that reduces temperature and radiation, enabling line-of-sight atomic beam generation in compact setups.

Findings

Atomic beam primarily travels forward with low divergence.

The device operates effectively at around 200 C.

The collimator shields radiation and moderates atomic velocity.

Abstract

Alkali metal dispensers have become an indispensable tool in the production of atomic vapors for magnetometry, alkali vapor cell clocks, and laser cooling experiments. A primary advantage of these dispensers is that they contain alkali metal in an inert form that can be exposed to air without hazard. However, their high temperature of operation (>600 C) is undesirable for many applications, as it shifts the atomic speed distribution to higher values and presents a radiative heat source that can raise the temperature of its surroundings. For this reason, dispensers are typically not used in line-of-sight applications such as atomic beam generation. In this work, we present an integrated rubidium dispenser collimating device with a thickness of only 2 mm that produces a beam of atoms traveling primarily in the forward direction. We find that the collimator plate serves to both shield the dispenser's radiation as well as to moderate the velocity of the atomic beam so that the measured longitudinal speed distribution is comparable to that of an ordinary alkali oven at only a slightly elevated temperature of 200 C. To confirm our theory, we also constructed another compact apparatus consisting of a dispenser and a silicon collimator and the measurements support our conclusion. Our integrated dispenser collimator will particularly be useful in integrated photonics and cavity QED on chip, where a localized, directed source of Rb vapor in small quantities is needed.