Detection of sodium in flames using laser polarisation spectroscopy and the influence of beam steering

Abstract

Laser spectroscopic techniques allow for sensitive and selective detection of atomic species in flames. This paper presents the results from a study of seeded sodium in a flame using single point Laser Polarisation Spectroscopy (LPS). Laser polarisation spectroscopy line shapes, as a function of pump beam fluence and saturation curves are presented for a sodium test species. In addition the influence of laser beam steering is investigated on the signal strength and spatial resolution of the technique. It is proposed that LPS would provide several advantages over traditional Laser Induce Florescence (LIF) where on resonance atomic detection is required in certain environments.