Laser-raman spectrum gas analyzer

Abstract

The invention provides a laser-raman spectrum gas analyzer. The laser-raman spectrum gas analyzer comprises a laser, an optical resonator, a hollow reflection pipe, a scattered light collecting device and a spectrograph. The laser emits laser beams to the optical resonator. The optical resonator is composed of optical resonator reflectors. The hollow reflection pipe is a hollow pipe containing gas to be analyzed and is placed between two of the optical resonator reflectors in the optical resonator, and the laser beams in the optical resonator enter the hollow reflection pipe from one end and are emitted out through the other end of the hollow reflection pipe. The laser beams in the optical resonator transmit in the inner wall of the hollow reflection pipe and act with the gas molecules to be analyzed in the hollow reflection pipe to produce scattered light; the scattered light is reflected by the pipe wall in the hollow reflection pipe for multiple times and then are emitted out from the two ends of the hollow reflection pipe. According to the laser-raman spectrum gas analyzer, the cavity length of the optical resonator is precisely adjusted through piezoelectric ceramics, an external incident laser beam longitudinal mode is locked, and enhanced laser beams are formed in the optical resonator; the enhancing effect is dozens of times or higher that of a pure optical resonator enhancing technology, and the sensitivity of gas detection is improved.

Description

technical field [0001] The invention relates to the field of analysis and detection of gas chemical components, in particular to a laser Raman spectrum gas analyzer. Background technique [0002] In 1928, C.V. Raman experiment found that the frequency of light passing through a transparent medium and being scattered by molecules changes. This phenomenon is called Raman scattering. In the scattering spectrum of a transparent medium, the frequency and the incident light frequency υ 0 The same component is called Rayleigh scattering; frequency symmetric distribution in υ 0 The spectral lines or bands on both sides are the Raman spectrum, in which the component υ with a smaller frequency 0 -Δυ is also known as the Stokes line, the component with a higher frequency υ 0 +Δυ is also called the anti-Stokes line. Since the number of Raman spectral lines, the size of the displacement, and the length of the spectral lines are directly related to the vibration or rotational energy l...

AI Technical Summary

Problems solved by technology

[0005] At present, the optimal detection sensitivity achieved by these technological inventions for enhancing the Raman scattering signal of gases is 1ppm, which is still not up to the application requirements of ppb level, such as the detection of volatile organic compounds (volatile organic compounds, VOC)

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