Laser-induced breakdown spectroscopy (LIBS) detection system based on dual-pulse defocusing pre-ablation

Abstract

The patent discloses a laser-induced breakdown spectroscopy (LIBS) detection system based on dual-pulse defocusing pre-ablation. Pulse laser is divided into two paths by a proportional beam splitter, wherein one path of laser passes through a defocusing light path, and the other path of laser passes through a delayed focusing light path. The first path of laser pulse, which passes through the defocusing light path, performs pre-ablation on a sample target surface to generate a circular flat surface with certain diameter, and the second path of laser pulse, which passes through the delayed focusing light path, is accurately focused on the flat surface to excite an LIBS effect. According to the LIBS system based on the dual-pulse defocusing pre-ablation, the influence of an ablation hole effect in traditional LIBS can be effectively eliminated, so that the LIBS detection precision is improved.

Description

technical field [0001] This patent relates to a laser spectrum detection method, in particular to a laser-induced breakdown spectroscopy (LIBS for short) detection system based on double-pulse defocusing pre-ablation. Background technique [0002] Laser-induced breakdown spectroscopy (LIBS) detection technology is to use the pulsed laser emitted by the pulsed laser to focus on the sample through the focusing lens, and obtain high-energy pulsed laser at the focal point, so that the sample is ablated, evaporated, excited and ionized to form Plasma sparks with high temperature, high pressure, and high electron density radiate a spectrum containing characteristic spectral lines of atoms and ions, which can be used to detect the elemental composition of matter. [0003] The traditional LIBS detection method uses low repetition frequency single pulse laser as the excitation source. In this method, when the pulse interacts with the sample target, ablation holes are generated due to...

AI Technical Summary

Problems solved by technology

[0003] The traditional LIBS detection method uses low repetition frequency single pulse laser as the excitation source. In this method, when the pulse interacts with the sample target, ablation holes are generated due to the ablation and evaporation of the high-energy laser pulse. After each laser pulse detection, As the depth of the hole increases, the roughness of the inner surface increases (called the ablation hole effect), which makes the LIBS spectral signal repeatability poor, which seriously affects the detection accuracy of LIBS. In addition, due to the scattering of the rough inner surface of the ablation hole, the LIBS will be reduced. SNR of detection

Images