Effect of ambient pressure on femtosecond laser-induced breakdown spectroscopy of Al in argon

The effects of ambient pressures on the intensity of spectral emission, electron temperature and density of femtosecond laser produced plasma have been investigated. For this purpose, Al targets were ablated by employing a Ti: Sapphire laser system (50fs, 800nm) under various filling pressures of argon gas. The optical emission spectroscopy of Al plasma has been studied using the Laser Induced Breakdown Spectroscopy (LIBS) system. The results indicate that the pressure of the ambient atmosphere is one of the controlling factors of the plasma plume characteristics. The measurements reveal also that some lines which are nearly unresolved at high pressures become well resolved at low pressures.