Overcoming the barrier of nanoparticle production by femtosecond laser ablation in liquids using simultaneous spatial and temporal focusing

There exist an increasing demand of industrial scale production of high purity ligand free nanoparticles due to the continuous development of biomedical, catalysis and energy applications. In this contribution, a simultaneous spatial and temporal focusing (SSTF) setup is firstly proposed for increasing nanoparticle productivity of the eco-friendly pulsed laser ablation in liquids (PLAL) technique. In spite of the fact that femtosecond pulses have proved to achieve higher ablation rates in air than picosecond pulses, in PLAL this is reversed due to the nonlinear energy losses in the liquid. However, thanks to the incorporation of SSTF, the energy delivered to the target is increased up to a 70%, which leads to a nanoparticle production increase of a 2.4 factor. This breaks a barrier towards the employment of femtosecond lasers in high efficiency PLAL.