Device and method for reducing fluorescent background of gas Raman spectrum

Abstract

The invention discloses a device and method for reducing a fluorescent background of a gas Raman spectrum.According to the device, a polarization modulation device conducts periodic polarization modulation on scattered light when a gas sample is analyzed; the intensity of a Raman signal of the gas sample with the good polarization characteristic periodically changes accordingly, the polarization direction of a fluorescence signal coming from the gas sample or a sample room or an optical element and the like has little correlation with the polarization direction of excitation light, and therefore the intensity of the fluorescence signal on a detector basically does not change along with rotating of the polarization modulation device; through a lock-in amplifying method, a gas Raman scattering signal can be detected in the fluorescent background.Accordingly, the influences of the fluorescent background can be reduced, and the detection capacity of the device on weak gas components can be improved; the device is simple and clear in structural layout and convenient to operate and has the very high practicability.

Description

technical field [0001] The invention belongs to the technical field of optical measurement, and more specifically relates to a device for reducing the fluorescence background of Raman spectrum, which is especially suitable for reducing the continuous noise caused by the fluorescence generated by optical elements and sample chambers in Raman scattering devices. Spectrum background. Background technique [0002] Raman scattering is an inelastic scattering phenomenon of photons. After a beam of monochromatic light is scattered by the sample medium, a scattered light with a specific frequency shift relative to the excitation light will be produced. The specific frequency shift corresponds to the energy between the vibration, rotation or electronic energy levels of the sample molecules / atoms Poor; therefore, the composition of the sample can be qualitatively or quantitatively analyzed by the Raman scattering technique. Raman scattering technology is widely used in environmental...

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Problems solved by technology

[0007] In view of the disadvantages of the Raman detection system in the prior art that are not conducive to the development of portability and miniaturization and insufficient detection capabilities for weak signals, the purpose of the present invention is to solve the above problems

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