Line shapes of saturated absorption spectra in hollow cathode discharges

Abstract

The saturated absorption line shapes of sputtered uranium atoms in hollow cathode discharges have been investigated using a single axial mode tunable CW laser. The spectral profiles observed under specific experimental conditions exhibit a marked deviation from the usual saturated absorption line shape function. These new features appear under the low velocity changing collision rate, high quenching rate and in the regime of strong pump saturation. A generalized line shape function based on population dynamics along with quenching mechanisms is derived and used to discuss the observed spectra. Our results suggest that the additional features in the observed spectra may be attributed to coherent effects which are manifested under suitable experimental conditions.