A system and method for multi-point multi-gas photoacoustic spectroscopy detection based on all-optical network

Abstract

The invention discloses a multi-point multi-gas photoacoustic spectrum detection system and method based on an all-optical network. The system comprises a light source generating module, a wave decomposition multiplexing module, N optical splitting modules, N photoacoustic pools, N optical microphones, a wave division multiplexing module, an optical signal receiving module and a plurality of optical fibers connected among the modules, wherein all the modules are connected in turn. The photoacoustic pools are used for generating the photoacoustic effect. A broad-spectrum light source comprisinga plurality of absorption peaks of the gas to be measured is demultiplexed so that a plurality of narrow-band light with different frequencies can be obtained. The narrow-band light is divided into two paths which are used as an excitation light source to generate photoacoustic signals. The photoacoustic signals are received and processed after wavelength division multiplexing, and the gas concentration information of the corresponding detection point can be obtained by analyzing the optical signals at different center frequencies and thus the multi-point multi-component detection of the gascan be realized.

Description

technical field [0001] The invention belongs to the technical field of gas detection, and more specifically relates to a multi-point multi-gas photoacoustic spectrum detection system and method based on an all-optical network. Background technique [0002] Photoacoustic spectroscopy is a spectroscopic technique based on the photoacoustic effect. In the photoacoustic effect, gas molecules absorb infrared light of a specific wavelength and are excited to a high-energy state. The molecules in the high-energy state convert the absorbed light to After the energy is converted into heat energy, it returns to a low-energy state. When the frequency of the incident light is modulated, the heat energy will show the same periodic change as the modulation frequency to generate sound waves. The sound signal is detected by the microphone and the final concentration of the gas is calculated. . [0003] In practical applications such as gas detection in pipe corridors, it is necessary to mo...

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Problems solved by technology

[0005] In view of the defects of the prior art, the purpose of the present invention is to provide a multi-point multi-gas photoacoustic spectroscopy detection system and method based on an all-optical network, aiming to solve the problem that the existing photoacoustic gas detection system can only detect a single point

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