Compact strontium atom source using fiber-based pulsed laser ablation

Abstract

We designed, demonstrated, and characterized a strontium atom source based on fiber-based pulsed laser ablation. By using a commercially available miniature lens system for focusing nanosecond pulsed laser of up to 225 μ J delivered through a multimode fiber of 105 μm core, we ablate a SrTiO3 target and generate a jet of neutral strontium atoms, though our method can be applied to other transparent ablation targets containing materials under concern. Our device endures 6000 cycles of pulse delivery and irradiation without noticeable damage on the fiber facets and lenses. The generated strontium beam is characterized with a spectroscopic method and is revealed to exhibit the transverse temperature of 800 K and a longitudinal velocity of 2300 m/s, which are typical for a pulsed-laser-ablation-based atom source. The number of atoms generated by a single ablation pulse is estimated to be 2×105. Our device provides a compact, cryo-compatible fiber-pigtailed atom source with minimized device footprints and reduced complexity of vacuum systems to further promote development of cold-atom experiments. It may also find interesting applications in atomic and molecular sciences.