Photon counting Raman spectrometer capable of realizing full spectrum direct-reading performance

Abstract

The invention provides a photon counting Raman spectrometer capable of realizing full spectrum direct-reading performance. The Raman spectrometer is mainly composed of a laser, a beam splitting system, a photon counting imaging detector, and information processing and display. The laser outputs laser to excite a sample to generate a characteristic Raman spectrometer; the beam splitting system carries out dispersion on incident composite light containing the characteristic Raman spectrometer so as to form a spectral intensity distribution image; on the basis of the position sensing detection and photon counting, photon counting imaging detector reconstructs a spectral intensity distribution image in a digitlization mode; and the information processing and display carries out a qualitative quantitative analysis on a sample according to positions and light intensity of all pixels in the digital spectral intensity distribution image. According to the invention, advantages of a photon counting property and a full spectrum direct-reading property are combined; therefore, advantages of low detecting limit, high reading precision, good data stability and large linear dynamic range are realized; and moreover, a plurality of substance components can be analyzed simultaneously; all spectral lines in a working wavelength range can be fully utilized; the working speed is fast; the structure is simple; and the operation stability is good.

Description

technical field [0001] The invention relates to a brand-new Raman spectrometer, that is, a photon counting full-spectrum direct-reading Raman spectrometer based on a "photon counting imaging detector". [0002] The invention is especially suitable for qualitative, quantitative and structural analysis of molecules, crystals and other substances, and can be widely used in many industries and technical fields such as environmental monitoring, food safety, bio-optics, metallurgy and chemical engineering, geological exploration, medicine and health. Background technique [0003] When light irradiates a substance, elastic scattering and inelastic scattering will occur: the scattered light of elastic scattering has the same wavelength as the excitation light, and this scattering is also called Rayleigh scattering; the scattered light of inelastic scattering has a component with a longer wavelength than the excitation light , there are also short components, the long ones are called...

AI Technical Summary

Problems solved by technology

[0030] 1) Raman spectrometers that use simple "charge integration method" for spectral analysis (such as detectors using CCD or CID or PD arrays, etc.), although the purpose of "full-spectrum direct reading" can be achieved, the corresponding "detection "Sensitivity" and "Data Stability" will be considerably limited, "Reading Accuracy" and "Linear Dynamic Range" will also be affected to a certain extent, and there is a serious signal overflow problem

[0031] 2) A Raman spectrometer that uses a simple "photon counting method" to perform spectral analysis in a scanning manner (for example, the detector uses PMT or APD, etc.), although the corresponding "detection sensitivity" and "data stability" can be greatly improved , "reading accuracy" and "linear dynamic range" can also be optimized to a certain extent, but "full-spectrum direct reading" cannot be achieved, and many advantages of "full-spectrum direct reading" cannot be achieved

Therefore, the advantages of the traditional Raman spectrometer are mainly reflected in the sensitivity, that is, high sensitivity (low detection limit); if the "photon counting method" is adopted, it also has good data stability, high reading accuracy, large linear dynamic range and no Affected by the signal overflow problem and other advantages; the disadvantage is that it cannot "full-spectrum direct reading", that is, it cannot analyze multiple material components at the same time, cannot make full use of every spectral line in the working wavelength range, slow working speed, complex structure, and stable operation Poor reliability (not suitable for on-site detection and online monitoring in harsh working conditions), relatively high production and operation costs, and cumbersome upgrades and adjustments, etc.

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