Experimental Investigation of the Self-Absorption Effect in Laser-Induced Breakdown Spectroscopy Based on Fiber Laser Ablation

Le résumé fourni par la source

Fiber laser is a stable light source for improving the stability of laser-induced breakdown spectroscopy (LIBS) under long-time operation. However, LIBS based on fiber laser ablation (FL-LIBS) also suffers from the self-absorption effect. In this paper, the self-absorption effect in FL-LIBS was experimentally investigated. The influence of the fiber laser ablation process on self-absorption was studied. The law of ablation on the surface of micro-alloy steel samples based on high pulse repetition rate (PRR) fiber laser ablation was qualitatively analyzed. The spectral data were explored based on the discrete wavelet transform and the spectral internal standard method. The result was an R2 of the calibration curve increasing from 0.955 to 0.995. The influence of the laser output power and defocus amount (DA) on the self-absorption effect was investigated. Through the adjusted selection of laser output power and single pulse ablation area (SPAA), compared with the situation when the laser was in focus, the system self-absorption factor can be reduced from 1.29 to 0.61, and the performance index of the calibration curve such as root mean squared error of cross validation (RMSECV) and relative standard variation (RSD) had been improved from 0.18 to 0.13 wt%, 6.61 to 5.88%, respectively. Finally, it was concluded that self-absorption would increase with the increase of laser output power and SPAA in high PRR FL-LIBS system, contrary to conventional LIBS based on low PRR laser ablation. This work investigated the mechanism and suppression of the self-absorption effect in FL-LIBS, aiming to promote the industrial application in the future.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.