Laser-induced fluorescence（LIF）has been used in plasmas for over 20 years and in plasma processing for about 10 years.It can be used in the diagnosis of plasma sources such as those used in etching,sputtering and thin film deposition.Among the possible measurements are ion density profiles,velocity distribution functions,convection and diffusion.LIF offers temporal and spatial ion distribution functions,allowing study of plasma thermodynamics,transportation and calibration of energy analyzers and mass flow probes.