Raman spectrum-based substance detection method

Abstract

In order to enhance the spectrum stability during theRaman spectrumsubstance analysis, the invention provides a Raman spectrum-based substance detection method which comprises the following steps: (1) generating a laser beam through a light source; (2) irradiating the laser beam in a sample to be detected so as to stimulate the Raman scattered light of the sample to be detected; (3) collecting the Raman scattered light to ensure that the Raman scattered light runs through an entrance slit and irradiates on a dispersion optical grating after being collimated by a collimating lens; (4) decomposing the polychromatic light into monochromatic lights with different wavelengths by the dispersion optical grating and converging the monochromatic lights onto a detection device; (5) converting the received light signal into an electric signal by the detection device; (6) processing the electric signal to obtain the spectral information of the lights with different wavelengths, and carrying out pretreatment to obtain the Raman spectrum of the sample to be detected. The detection method is accurate and reliable, has high reproducibility and ultrahigh analytic sensitivity, is suitable for the detection of ultra-trace samples and is capable of correctly obtaining the detection result.

Description

technical field [0001] The present invention relates to a material composition analysis method, more specifically, to a material detection method based on Raman spectroscopy. Background technique [0002] Raman spectroscopy has demonstrated powerful capabilities in non-destructive physical property analysis and identification. However, due to the lack of low-cost, robust, reliable and stable semiconductor lasers that can provide high spectral line brightness, the application of Raman spectrometers has been hindered to some extent. Here the spectral line brightness is defined as: laser power divided by its spectral line width. A wide stripe or wide area semiconductor laser (eg typical stripe width at 20 = 500 microns) can provide high output power > 1 Watt. However, because there are a large number of excitation modes in the Fabry-Perot (F-P) laser resonator, its spectral line width is on the order of several nanometers or wider. This broad linewidth limits the use of b...

AI Technical Summary

Problems solved by technology

However, these external cavity resonant laser structures are sensitive to alignment accuracy of optical components (such as lens and grating orientation), temperature fluctuations, and vibrations, resulting in poor mechanical and temperature stability.

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