Fullerene functionalized gold nanoparticles for optical limiting of continuous wave lasers

Due to the increasingly widespread diffusion of lasers in many scientific and technological fields, the engineering and the fabrication of systems able to protect either human eyes or delicate equipment from laser radiation damage is nowadays attracting lots of interest in the scientific community. In this work, the optical limiting properties of fulleropyrrolidine, gold nanoparticles and hybrid systems in solution and in a polycarbonate matrix are investigated using a continuous wave laser at 514 nm, by optical limiting, Z-scan and temporal response measurements. The comparison of the results, obtained with different techniques, has allowed us to show that thermal effects account for most of the nonlinear response in gold nanoparti- cles and in the hybrid system; moreover, the latter exhibits a lower nonlinear threshold and a faster response compared to the former. This paper provides a contribution to the engineering of efficient protection devices in the continuous wave regime.