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A Dual-Domain Multiplexed QEPAS System for Multispecies Gas Detection Based on Wavelength-Selective LPFG
Chong Niu1,2, Chupeng Lu3, Haiyue Sun1,2
1Zhengzhou Advanced Research Institute, Harbin Institute of Technology, Zhengzhou 450008, China.
None:
We propose a novel method for trace detection of multicomponent gases by combining optical mode multiplexing based on long-period fiber gratings (LPFGs) with frequency multiplexing of quartz tuning forks (QTFs). By leveraging the advantages of LPFGs, including flexible mode selection and high mechanical robustness, a three-channel LPFG-based quartz-enhanced photoacoustic spectroscopy (LPFG-QEPAS) sensor was constructed for the first time to simultaneously detect H2O, CH4, and C2H2, with minimum detection limits (MDLs) of 4.85, 8.12, and 2.88 ppm, respectively. This work represents the first integration of optical fibers with a QEPAS system for multicomponent trace gas detection. Featuring no requirement for complex and precise spatial optical alignment and allowing flexible selection of target gas components, this method is expected to be highly valuable for multicomponent, multifunctional gas sensing applications.
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