Laser-induced thermal source for cold atoms

TL;DR

This paper introduces a compact laser cooling method using laser-induced thermal ablation of a solid granule, enabling efficient trapping of cold atoms with potential applications in quantum technologies.

Contribution

The paper presents a novel laser ablation technique for atom cooling and trapping, demonstrating high atom numbers and long trap lifetimes with a simple setup.

Findings

Achieved trapping of 3.5 million strontium atoms

Trap lifetime exceeds 4 seconds

Demonstrated rapid recovery of vacuum conditions

Abstract

We demonstrate a simple and compact approach to laser cool and trap atoms based on laser-induced thermal ablation (LITA) of a pure solid granule. A rapid thermalisation of the granule leads to a fast recovery of the ultra-high vacuum condition required for a long trapping lifetime of the cold gas. We give a proof-of-concept of the technique, performing a magneto-optical trap on the 461 nm $^1S_0\rightarrow^1P_1$ transition of strontium. We get up to 3.5 million of cold strontium-88 atoms with a trapping lifetime of more than 4 s. The lifetime is limited by the pressure of the strontium-free residual background vapour. We also implement an original configuration of permanent magnets to create the quadruple magnetic field of the magneto-optical trap. The LITA technique can be generalized to other atomic elements such as transition metals and lanthanide atoms, and shows a strong potential for applications in quantum technologies ranging from quantum computing to precision measurements such as outdoor inertial sensing.