Actualizado: 11 de oct de 2018
A low cost LIBS equipment with burst-mode Q:Switched Nd:YAG laser as excitation source is presented. The results of investigation on several materials using laser emission plasma excited under normal atmospheric conditions are presented. It is shown that the intensity of emission significantly enhance with the laser burst. This regime leads to increasing signal to background ratio due to subsequent plasma excitation by high power short pulses increasing intensity of atomic lines.
The highest fluency and the shortest duration of the pulses obtained by a multi-pulse laser with a Q-switch enabled more efficient ablation of the material than that obtained in the free-generation mode.
On the other hand, the quality of the voids―characterized by the non-existence of remains or edges caused by the ablation process―were obviously improved as a result of the multi-pulse mode, which was an expected result due to shorter duration of the pulses and, therefore, heat transfer with a consequent thermal effect. If we take into account that multi-pulse irradiation was obtained using a Q-switch, which is characterized by its simplicity, low cost and robustness, the potential of using this laser emission regime in dentistry becomes evident.