Comparative Research On LIBS Of Metal Elements Excited By Nanosecond Laser And Femtosecond Laser

Laser-induced breakdown spectroscopy(LIBS), a technique applying to analyzing the atomic lines, molecule lines or ionic lines in the transient plasma emission excited by the ablation of investigated substance with high-power laser, has been an active and promising research area and developing rapidly because of the excellent advantages of enabling measurement and quantitative analysis for unknown substance. Since LIBS for detecting elements in any physical state of the material requires less sample quantity and no sample preparation and causes little damage, it is suitable to be applied to realize the fast analysis, high sensitivity, on-line and real-time detection either under the condition of remote telemetry or in harsh circumstance. The present dissertation studies the influence of different laser sources on LIBS detection, comparing the signal differences between LIBS excited by femtosecond and nanosecond laser separately with quantitative analysis method.Element Ce in glass was taken as the detection target, the experiment system of LIBS was set up successfully and the optical path was adjusted perfectly. Collect the LIBS spectroscopy of Ce excited by nanosecond laser and femtosecond laser to obtain the best detection results. Based on the time-resolved spectra, the Ce I 308.36 nm spectra date of different concentrations were measured and the standard curves of peak intensity and integrated intensity were analyzed with traditional direct intensity calibration method. The two curves of glass sample of 0.08 mol Ce is analyzed calibratedly. The obtained results suggested that femtosecond laser induced breakdown spectroscopy could be taken as a suitable s cheme for quantitative analysis, the measured result of Ce was relative accuracy.Finally, dissertation assisted LIBS is discussed for detection of heavy metals in aqueous solutions. Liquid phase was transformed into solid phase by filter paper, to realize the goal of detecting the Cu element in liquid and obtaining it s calibration curve. With the time-resolved spectra of different concentrations, Cu I 324.8nm and II 327.4nm spectra date was added to be fitted, improving the limit of detection.