Highly sensitive methane detection using a mid-infrared interband cascade laser and an anti-resonant hollow-core fiber


Gomółka G., Stępniewski G., Pysz D., Buczyński R., Klimczak M. and Nikodem  M.


For over a decade hollow-core fibers have been used in optical gas sensors in the role of gas cells. However, very few examples of actual real-life applications of those sensors have been demonstrated so far. In this paper, we present a highly-sensitive hollow-core fiber based methane sensor. Mid-infrared distributed feedback interband cascade laser operating near 3.27 µm is used to detect gas inside anti-resonant hollow-core fiber. R(3) line near 3057.71 cm-1 located in ν3 band of methane is targeted. Compact, lens-free optical setup with an all-silica negative curvature hollow-core fiber as the gas cell is demonstrated. Using wavelength modulation spectroscopy and 7.5-m-long fiber the detection limit as low as 1.54 ppbv (at 20 s) is obtained. The demonstrated system is applied for a week-long continuous monitoring of ambient methane and water vapor in atmospheric air at ground level. Diurnal cycles in methane concentrations are observed, what proves the sensor’s usability in environmental monitoring.

Optics Express, 2023, vol. 31(3), pp. 3685-3697, doi: 10.1364/OE.479963

Opublikowano dnia - 25 stycznia 2023 13:35
Ostatnia zmiana - 27 stycznia 2023 14:20
Publikujący - Sekretariat IGF