Femtosecond laser-induced breakdown spectrum generation and acquisition system based on space-time shaping

Abstract

The invention discloses a femtosecond laser-induced breakdown spectrum generation and acquisition system based on space-time shaping, and belongs to the technical field of femtosecond laser application. A Bessel light beam with a long focal depth is used for exciting material plasmas after being shrunk; under the condition that focusing is not carried out, plasma excitation with the same energy density is achieved at different height positions of a sample, the process of single-point independent focusing is omitted, possible human and machine errors in each time of focusing operation are avoided, and the stability, repeatability and collection efficiency of spectrum collection are guaranteed. The system can adjust parameters of the conical lens and the beam shrinking lens group to obtain Bessel regions with different focusing lengths, and a device suitable for samples with different height change ranges is designed according to individual requirements. When a femtosecond laser Bessel beam is adopted to excite plasmas on the surface of a rough sample, the combination of a half-wave plate and a Glan-Taylor prism in the system realizes the continuous linear adjustment of pulse energy,and realizes the sample detection and analysis under the nearly lossless condition.

Description

technical field [0001] The invention relates to a femtosecond laser-induced breakdown spectrum generation and collection system, which belongs to the technical field of femtosecond laser applications. Background technique [0002] Laser-induced breakdown spectroscopy (LIBS) has developed rapidly in recent years, mainly due to its advantages of simple operation, no need for sample preparation, real-time online monitoring, and simultaneous analysis of multiple elements. It is also used in environmental monitoring, cultural heritage analysis and identification, It is widely used in fields such as biological and medical identification and space exploration. Its basic principle is to obtain the elemental information carried by analyzing the plasma light generated during the ablation process of the sample, so as to perform qualitative and quantitative detection of specific components in the sample. [0003] Femtosecond laser has the advantages of small heat-affected zone and high...

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Problems solved by technology

[0004] However, in practical applications, most of the samples to be detected are non-smooth surfaces with large surface height changes, and the spectrum itself has certain fluctuations, which makes it difficult to excite and collect spectra on rough sample surfaces

If the focus needs to be adjusted separately during each spectrum collection, then both the spectrum generating device and the collection device need to be adjusted, and the human and machine errors that may exist in each focusing operation will bring a lot of trouble to the detection

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