Laser-induced thermal source for cold atoms

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 $$^1S_0\rightarrow \,^1P_1$$ 1 S 0 → 1 P 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.

High flux strontium atom source

“…A potential solution to achieve miniaturization of the cold atomic jet is to replace the oven with a resistively heated dispenser [6] or laser-controlled atomic desorption from a solid atomic source [7,8]. Still, the large velocity dispersion requires to either slow atoms or select a small velocity class of atoms.…”