Method to measure the electric field vector in an argon glow discharge using laser polarization spectroscopy

A method for measurement of the direction of the electric field in a glow discharge is reported. This method uses the dependence of the electronic excitation spectrum of argon atoms on the polarization of the laser radiation. In this research, laser radiation was used to excite argon atoms in a plasma from the 4s [3 / 2](2) metastable level to Rydberg levels, and excitation spectra were measured using laser optogalvanic (LOG) spectroscopy. In addition, LOG spectra of argon atoms interacting with an electric field were calculated by solving the Schrödinger equation. Good agreement was found between experimental and theoretical LOG spectra obtained for different polarizations of the laser radiation.