Laser defocusing amount automatic adjusting device on micrometer scale and adjusting method thereof

Abstract

The invention relates to the technical field of atomic emission spectroscopy, and in particular relates to a laser defocusing amount automatic adjusting device on the micrometer scale and an adjustingmethod thereof. The device comprises a laser pen. A beam shaping system and a beam splitter are arranged on a central axis of the laser pen which emits a laser beam. The angle between the beam splitter and the laser beam of the laser pen is 45 degree. The upper and lower sides of the beam splitter are provided with a microscopic imaging optical system for observing the surface topography of the sample and detecting the laser spot of the sample surface. A three-dimensional stage for carrying a sample is disposed under the microscopic imaging optical system, and the microscopic imaging opticalsystem and the three-dimensional stage are electrically connected to a control host. The microscopic imaging optical system comprises a CCD camera and a microscope objective located on the upper and lower sides of the beam splitter. According to the laser defocusing amount automatic adjusting device on micrometer scale and adjusting method thereof, the CCD camera can be used to acquire and judge images in real time, and the laser defocusing amount is corrected in real time, which has great significance for ensuring the consistency of the plasma morphology on the sample.

Description

Technical field: [0001] The invention relates to the technical field of atomic emission spectrometry detection, in particular to an automatic adjustment device and an adjustment method for laser defocus at the micron scale. Background technique: [0002] Laser-induced breakdown spectroscopy microanalysis technology has the advantages of fast analysis speed, simple sample preparation, convenient use and maintenance, etc., and can make up for the shortcomings of traditional microanalysis methods. In recent years, it has received a lot of attention. The microcosmic mechanism of the interaction between laser and matter is relatively complicated. The difference in the defocus amount of the laser on the sample surface directly leads to the difference in the power density of the laser focusing on the sample surface, so that the internal parameters of the excited plasma (electron density, plasma temperature, Ion density, etc.) and the resulting plasma morphology are quite different...

AI Technical Summary

Problems solved by technology

In the specific micro-area analysis, the laser beam is generally tightly focused on the sample surface through the microscope objective lens, so that the generated plasma form is extremely sensitive to the defocus amount of the sample surface, resulting in the instability of the spectral lines collected by the detector, which is extremely large. The results of qualitative and quantitative analysis of the influence of material composition

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