Research On Anti-resonant Fiber-enhanced Multigas Raman Sensing

With the proposal of the concept of green industry,under the guidance of the concept of green industry,it is necessary to carry out real-time online monitoring of industrial gases with complex components in the project,so as to prevent industrial polluting gases with excessive content from being discharged into the atmosphere and cause pollution,so as to promote the development of green industry.Gas sensors are widely used in the detection of toxic,harmful,flammable and explosive gases.Among them,optical fiber gas sensors are produced based on optical fiber sensing technology.Compared with traditional sensors,optical fiber sensors have the advantages of compact structure,light weight,high sensitivity,anti electromagnetic interference,electrical insulation,good corrosion resistance,fast measurement speed,large information capacity,and it can realize remote monitoring and protect the safety of personnel.Optical fiber sensors are widely used in harsh environments that traditional electrochemical sensors cannot apply,such as flammable and explosive,electromagnetic interference,narrow space and so on.In recent years,optical fiber sensor combined with Raman spectrum for multicomponent gas detection is the research hotspot of optical fiber gas sensor,and the research results show that optical fiber enhanced gas Raman spectrum has obvious advantages for multi-component gas detection.In this paper,a multi-component gas Raman sensing system based on nodeless hollow core fiber is used.The main research contents of this paper are as follows:（1）The optical path of the transmission optical fiber enhanced gas Raman system is built,the parameters such as the length of the optical fiber and the incident laser power are changed,the basic law of the anti-resonant optical fiber enhanced Raman signal is explored based on the transmission system,and the effective length model of the hollow core optical fiber enhanced gas Raman system is proposed.（2）The problem of silica Raman signal in anti-resonant fiber is studied,and the self-filtering characteristics of anti-resonant fiber are studied.A spatial filtering system is designed for short length optical fiber,which effectively filters out the silica Raman signal.（3）The detection ability of CO₂ gas isotopes in the environment based on 5m long hollow core anti-resonant fiber enhanced gas Raman system was tested.（4）A reflective optical fiber gas Raman sensing system is built to realize the rapid detection of multi-component gas,and the basic law of gas filled hollow fiber is studied.