基于梳状滤波器的光纤甲烷传感器的研究

Research on fiber optical methane sensor based on comb filter

采用基于Sagnac的保偏光子晶体光纤(polarization-maintaining photonic crystal fiber,PM-PCF)滤波器,将宽带光源精确匹配甲烷气体在近红外波段的几个吸收线谱。设计出一个简单合理的多反射气室,使得光源和甲烷气体之间能够充分相互作用,提高了系统的灵敏度。同时,在测量甲烷气体浓度时,加入乙炔气体作为干扰,通过实验验证了该方案能够有效减缓交叉气体的灵敏度。

The paper used a polarization-maintaining photonic crystal fiber（PM-PCF） based Sagnac loop filter to slice the spectrum of a broadband light source so as to match the several absorption lines of the methane gas within the near-infrared band. It designed a compact, cost-effective and multiple reflections gas cell to enhance the interaction between the light and the methane gas, which also subsequently increased the system sensitivity. Moreover, by intentionally pumping the acetylene gas into the gas cell during the methane gas concentration measurement, effective mitigation of cross gas sensitivity is experimentally verified.