Laser radar for determining atmosphere NO2 concentration based on raman light source differential absorption method

Abstract

The invention discloses a laser radar for measuring atmospheric NO2 concentration based on the differential absorption method of a Raman light source, which includes a rotating Raman laser source, a light receiving and light splitting component, and a photoelectric detection and control processing part, and is characterized in that: the light receiving The light-receiving telescope tube receives the backscattered light from the atmosphere with the light-splitting part, and the incident fiber is coupled to guide the light into the focal plane of the lens, collimated by the lens and injected into the grating, and splits the light with two wavelengths of 354.71nm and 360.00nm After exiting, it is received by two outgoing optical fibers located at the focal plane of the lens; the grating is a blazed grating, which has a certain angle with the lens; the photoelectric detection and control processing part includes a microcomputer, a data acquisition card, a delay device, an amplifier Shaping circuit, photomultiplier tube and photoelectric probe. The invention has the beneficial effects of simple structure, low cost, high diffraction efficiency, good flexibility, convenient use and maintenance, and the like.

Description

technical field [0001] The invention relates to the field of laser detection, in particular to the detection of atmospheric NO 2 Concentration lidar, specifically a differential absorption method based on Raman light sources to measure atmospheric NO 2 Concentration lidar. Background technique [0002] NO 2 Gas is a major pollutant of the atmosphere, but its instability of easy oxidation and decomposition brings certain difficulties to real-time monitoring. Therefore, the current domestic detection methods for nitrogen oxides are mostly chemical methods, such as naphthalene ethylenediamine hydrochloride spectrophotometry, chemiluminescence and galvanic coulometric titration, etc., but these methods need to be measured in the laboratory, and the real-time performance is poor Meet the requirements of online measurement. Lidar technology to measure the concentration of air pollutants has been a hot spot in the past two years. It is usually measured by differential absorptio...

AI Technical Summary

Problems solved by technology

Among them, the double-grating monochromator is widely used because it can well suppress Rayleigh scattering and improve the signal-to-noise ratio. come error

At the same time, the double grating monochromator uses two gratings to split the light, which increases the system cost

The input and output light of the re-split system are usually coupled by optical fibers, and the relative position of the end face of the optical fiber at the focal plane of the lens will also affect the diffraction efficiency and splitting effect

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