Experiments

Intense laser interaction with structured targets and high field plasmonics

This research activity is focused on the use of sub-wavelength structuring to enhance the coupling of intense, ultrashort laser pulses with solid matter. In particular, it aims to exploit plasmonic excitation in a regime of high fields where the electron dynamics is nonlinear and relativistic. The interaction of tailored nanostructured targets can result in the absorption of nearly 90% of laser energy and in plasmas significantly denser and hotter than those usually obtained with flat targets. Applications include the development of laser driven sources of energetic radation (ions, electrons, X- and gamma-rays) and the possibility to manipulate high electromagnetic fields allowing further enhancement. The acitivity includes both theoretical and experimental work. The theory and simulation activity is strongly based on the development of particle-in-cell codes and their use on supercomputers. The experimental activity, in collaboration with foreign groups, exploits the potential of high-contrast femtosecond laser systems.

Increase in the energy of emitted protons in a grating target with respect to a flat one. The maximun enhancement is found around the resonant angle for the excitation of surface waves. Ref: Ceccotti et al, Phys. Rev. Lett. 111 (2013) 185001

Silicon Nanowire target