Abstract

We apply frequency-shifted interferometry to interrogate multiple gas sensors along a single fiber. This method uses a tunable continuous-wave laser and a slow detector, and allows spectral overlap of sensors. It can be used to quantify the concentrations of single or different gas species at multiple locations. A three-sensor system was used to demonstrate this capability, achieving a minimum detectable acetylene concentration of 230 ppm with a 3-cm gas cell, or equivalently, 6.9 ppm$\cdot$m. The design considerations in the implementation and the system parameters are also discussed.

© 2009 IEEE

Multipoint sensing with a low-coherence source using single-arm frequency-shifted interferometry

Yiwei Zhang, Fei Ye, Bing Qi, and Li Qian
Appl. Opt. 55(21) 5526-5530 (2016)

Multichannel continuous-wave fiber cavity ringdown gas sensing utilizing frequency-shifted interferometry

Z. Y. Yang, C. F. Cheng, H. Lv, Z. H. Chen, J. X. Chen, and Y. W. Ou
Appl. Opt. 57(35) 10224-10229 (2018)

Multipoint dispersion spectroscopic gas sensing by optical FMCW interferometry

Xiutao Lou, Yue Wang, and Yongkang Dong
Opt. Lett. 46(23) 5950-5953 (2021)

Multi-point spectroscopic gas sensing based on coherent FMCW interferometry

Xiutao Lou, Yabo Feng, Chen Chen, and Yongkang Dong
Opt. Express 28(6) 9014-9026 (2020)

Cryogenic fluid level sensors multiplexed by frequency-shifted interferometry

Fei Ye, Tong Chen, Di Xu, Kevin P. Chen, Bing Qi, and Li Qian
Appl. Opt. 49(26) 4898-4905 (2010)