Research On Portable Methane Sensor Based On High Q Resonator

Nowadays gas explosion has been the most serious matter which restricts the development of the mining industry in our country. So detecting the origin, leak and density of methane (the main component of gas) in time is crucial to the safety of mining industry and personal security and safety.Based on our own patent of Pro. YaoMeng from ECNU, infrared spectrum absorption theory and a portable sensor for detecting methane density had been demonstrated. The method of integration for absorption spectrum sensor technology and optical resonator had been brought up by Pro. YaoMeng. This dissertation researched a portable methane sensor based on high Q optical resonator .The key for this kind of sensor is to improve the gas cell in the traditional optical methane sensor in which gas cell was required a lager size for heat dissipation. The improvement ,to a great extent ,is able to replace the traditional optical methane sensor .The software of Ansoft HFSS was used to simulate the mini methane absorption cell based on high Q. The results from simulation verified that the light dots don't focus on somewhere , but distribute randomly on the cancave of gas cell. In this way , system resolved the difficulty that accumulated great heat caused damage of optical components for focused light dots in traditional optical methane sensor and raised the service life of sensor. This also resolved the problem that traditional optical methane sensor required a large size for gas cell to release heat. The improved mini methane cell has the following advantages, such as long lifetime, simple optical structure, small size and portability. Through the improved for gas cell, optical methane sensor is not only used to detect the methane density in lab but also in actual environment. The paper also simulated some kind of other mini gas cells with different Q .All of results from simulate verified that the distribution of E_Field in cell is consistent with analysis in theory. Therefore the mini methane cell based on multi_pass resonated cavity is feasible and realizable. Especially, when the simulate is doing for mini cell under the condition of low Q, we still obtain the clear and reliable results. So this supply a wild_range condition for actual optical components...