Characteristic Diagnostics of a Laser-Stabilized High-Pressure Argon Plasma by Optical Emission Spectroscopy

Laser-stabilized plasma (LSP) attracts intense interests in lighting applications requiring extreme stability, long lifetime, and broad radiation range (
$10^{1}$
–
$10^{4}$
nm). In this work, an argon LSP was generated at high pressures (>10 bar) by a focused laser beam, and its fundamental properties were studied in detail by the approach of optical emission spectroscopy (OES), with emphasis on the determination of plasma parameters including the electron temperature and density. The effects of argon gas pressure, laser power, and N2 mixture ratio, on the full-view of radiation spectra and electron parameters, were investigated experimentally. The results demonstrate that the increase of gas pressure or laser power density is a proper way to achieve higher optical radiation from the argon LSP, but not by adding molecular mixtures like N2.