Compact atom source using fiber-based pulsed laser ablation

TL;DR

This paper presents a compact, fiber-based pulsed laser ablation atom source capable of generating neutral strontium atoms with high durability, reduced size, and compatibility with cold-atom experiments, using a simple, fiber-pigtailed design.

Contribution

The authors developed and demonstrated a durable, fiber-coupled pulsed laser ablation atom source that is compact, cryo-compatible, and suitable for cold-atom research, with detailed characterization.

Findings

Able to endure 6,000 laser pulses without damage

Produces a strontium atom beam with transverse temperature of 800 K

Generates approximately 2×10^5 atoms per pulse

Abstract

We designed, demonstrated, and characterized an atom source based on fiber-based pulsed laser ablation. By using commercially available miniature lens system for focusing nanosecond pulsed laser of up to 225~$\mu$J delivered through a multimode fiber of 105~$\mu$m core, we successfully ablate a SrTiO$_3$ 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 6\,000 cycles of pulse delivery and irradiation without noticeable damage on the fiber facets and lenses. The generated strontium beam is characterized with spectroscopic method and is revealed to exhibit the transverse temperature of 800~K and longitudinal velocity of 2\,300~m/s, which are typical of pulsed-laser-ablation-based atom source. The number of atoms generated by a single ablation pulse is estimated to be $2\times 10^5$. Our device provides a compact, cryo-compatible fiber-pigtailed atom source with minimized device footprints and reduced complexity of vacuum systems to further promote the developments of cold-atom experiments. It may also find interesting applications in atomic and molecular sciences.