Efficient atomization of cesium metal in solid helium by low energy (10 $\mu$J) femtosecond pulses

TL;DR

This paper demonstrates that low-energy femtosecond laser pulses can efficiently produce cesium atoms in solid helium with minimal matrix perturbation and higher atomic densities compared to traditional nanosecond laser sputtering methods.

Contribution

It introduces a novel, low-energy femtosecond laser technique for atomizing cesium in solid helium, reducing perturbation and increasing atomic yield.

Findings

Femtosecond pulses as low as 10 μJ effectively atomize cesium.

Reduced matrix perturbation compared to nanosecond laser sputtering.

Higher atomic densities achieved with femtosecond laser method.

Abstract

Metal atoms in solid and liquid helium-4 have attracted some interest either as a way to keep the atoms in a weakly perturbing matrix, or using them as a probe for the helium host medium. Laser sputtering with nanosecond pulsed lasers is the most often used method for atom production, resulting however in a substantial perturbation of the matrix. We show that a much weaker perturbation can be obtained by using femtosecond laser pulses with energy as low as 10 $\mu$J. As an unexpected benefit, the atomic density produced is much higher.