Laser-synthesized carbon nanoparticles for nonlinear optical limiting effect

Abstract

Nonlinear optical limiting materials have attracted much research effort during recent decades for promising applications in a broad range of areas such as safety protection from intense laser light and nonlinear optical devices for optical processing. Carbon nanomaterials such as carbon nanotubes were demonstrated as excellent candidates for wide-band optical limiting effect towards intense laser irradiation. However, these carbon nanomaterials used previously either have a large size distribution or possess a large aspect ratio, which bring about complex nonlinear optical limiting mechanisms. In this project, uniform carbon nanoparticles were produced by pulsed laser ablation of a bulk target in different environments to study their nonlinear optical limiting properties. A variety of techniques such as transmission electron microscopy, Raman spectroscopy and UV-Vis spectroscopy were used to characterize the nanoparticles obtained. Strong nonlinear optical limiting effect was observed towards 7-ns laser pulses. Influencing factors such as the repetition rate of laser pulses and the nanoparticle concentrations on the limiting performance were included in the study. The physical origin of nonlinear optical limiting for carbon nanoparticles was investigated with time-resolved analysis and theoretical calculations. This study provides useful information for using carbon nanoparticles as novel nonlinear optical limiting materials in areas such as laser eye protection and optical communication.