INFLUENCE OF ATMOSPHERE AND IRRADIATION WAVELENGTH ON COPPER PLASMA EMISSION INDUCED BY EXCIMER AND Q-SWITCHED ND-YAG LASER-ABLATION

Laser-induced copper plasma emission was investigated by time-integrat ed spatially resolved spectrometry, The comparative work on the plasma emission characteristics-specifically, self-absorption, line broadeni ng, emission intensity, and metal ion formation-was carried out by the use of two different laser systems (XeCl excimer: lambda = 308 nm; Nd :YAG: lambda = 1064 and 532 nm), The characteristics of plasma emissio n produced by different wavelength radiation on copper atomic and ion lines under various atmospheric gases (argon, neon, and helium) and pr essures (760-10 Torr) are presented, The differences in self-absorptio n and line broadening phenomena in the plasma location were explained by shock wave-driven excitation mechanism for atoms in the outer regio n in the plasma, The excitation temperatures of the plasma induced by 308- or 532-nm irradiation were also much higher that those induced by 1064-nm irradiation.