Saturation measurements of the a 3P 0–y 3D 1o Ti I transition by optogalvanic spectroscopy

Abstract

The optogalvanic signal (OGS) induced in a Ti–Ar hollow-cathode discharge, stimulated by modulated cw laser light tuned to the a 3P 0–y 3D 1 o Ti I transition, was measured as a function of the light intensity. By solving analytically the rate equations of a three-level system, which include the Ti I ground state, the lower metastable a 3P 0 and the upper y 3D 1 o levels, an expression was obtained that relates the magnitude of the OGS to the laser intensity and the saturation parameter (1/ σ 0 τ). The σ 0 τ product was determined by fitting the theoretical curve to the experimental data.