Laser excitation spectrum detecting probe and spectrum detecting method

Abstract

The invention discloses a laser excitation spectrum detection probe, comprising: a laser, an optical path conversion device, a collection and collection device, a coupling filter device, and a spectrometer; the laser is used to output laser beams with inconsistent divergence angles in the long and short axis directions; the optical path conversion device, Set on the output optical path of the laser beam, it is used to change the transmission route of the incident light; the gathering and collecting device is used to gather the light beam reflected by the optical path conversion device at the focal point where the sample is placed; the coupling filter device is set on the optical path conversion Between the device and the spectrometer, it is used to optically couple the collected light beams and gather the formed strip spot at the slit of the spectrometer. The invention can improve the coupling efficiency of the spectrometer, improve the system collection efficiency; reduce the cost of devices and instruments, and improve the tolerance performance of the system; reduce the power density of the converging laser spot, prevent heat accumulation and sample burning; increase the sampling range, and are more suitable for Sampling of solid mixture samples and sparse samples.

Description

technical field [0001] The invention relates to the technical field of laser excitation spectrum detection, in particular to a laser excitation spectrum detection probe and a spectrum detection method. Background technique [0002] Laser excitation spectroscopy detection technology includes Raman spectroscopy, fluorescence spectroscopy, and plasma spectroscopy. Laser light sources are used as excitation light sources for these optical phenomena. comprehensive performance of the device. Spectrum analyzers based on gratings / prisms are currently the most widely used spectral detection equipment, and their optical structures mainly include: slits, collimating optical systems, gratings / prisms, collection optical systems, detectors / detector arrays; various types of lasers , there are semiconductor lasers, solid-state lasers, fiber lasers, etc.; and the laser output from the laser is mostly axisymmetric parallel light after various treatments and finally converges into a circular ...

AI Technical Summary

Problems solved by technology

Spectrum analyzers based on gratings / prisms are currently the most widely used spectral detection equipment, and their optical structures mainly include: slits, collimating optical systems, gratings / prisms, collection optical systems, detectors / detector arrays; various types of lasers , there are semiconductor lasers, solid-state lasers, fiber lasers, etc.; and the laser output from the laser is mostly axisymmetric parallel light after various treatments and finally converges into a circular spot. The energy of the excitation signal that is finally coupled into the spectrometer is limited. slit, such as figure 1 As shown, most of the energy is blocked by the slit and cannot enter the subsequent analysis system, which greatly reduces the collection efficiency of the system

[0003] In order to achieve higher efficiency, the usual practice is to strictly control the divergence angle of the laser, so that it can be converged at a very small divergence angle to achieve the smallest possible converging spot, which will lead to an increase in the manufacturing cost of the laser, and a very small converging spot. If the energy density is too high, it is easy to ignite the sample to be tested, and the small sampling range is not conducive to the measurement of mixed solids, and the focus depth of the system is small, and the system tolerance is small, etc.

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