Kilohertz laser ablation for doping helium nanodroplets

TL;DR

This paper introduces a high-repetition-rate laser ablation method for doping helium nanodroplets, enabling the incorporation of refractory materials and biomolecules for spectroscopy.

Contribution

It presents a novel laser ablation setup operating at kilohertz rates, capable of doping helium nanodroplets with refractory metals and biomolecules, expanding experimental possibilities.

Findings

Efficient doping of helium droplets with refractory metals like titanium and tantalum.

Successful doping with non-volatile biomolecules such as Guanine.

Demonstrated stable operation suitable for spectroscopic applications.

Abstract

A new setup for doping helium nanodroplets by means of laser ablation at kilohertz repetition rate is presented. The doping process is characterized and two distinct regimes of laser ablation are identified. The setup is shown to be efficient and stable enough to be used for spectroscopy, as demonstrated on beam-depletion spectra of lithium atoms attached to helium nanodroplets. For the first time, helium droplets are doped with high temperature refractory materials such as titanium and tantalum. Doping with the non-volatile DNA basis Guanine is found to be efficient and a number of oligomers are detected.