Optical emission spectroscopy of femtosecond pulsed laser produced aluminum plasma

Abstract

A high purity aluminum target placed inside a vacuum chamber maintained at a base pressure of ~10^-2 mbar was ablated using a mode-locked Ti:sapphire femtosecond laser with an output wavelength centered at 786 nm, pulse repetition rate of 80 MHz and pulse duration of around 100 fs. The resulting plasma plume was then analyzed via optical emission spectroscopy. The spectra showed emission peaks corresponding to aluminum at 488.13 nm and 526.66 nm, 488.13 nm and 526.66 nm; nitrogen 287.17 nm and 765.48 nm; and oxygen at 715.95 nm and 967.75 nm. The presence of emission peaks from nitrogen and oxygen is attributed to performing ablation in a low vacuum environment.