Direct performance comparison of antiresonant and Kagome hollow-core fibers in mid-IR wavelength modulation spectroscopy of ethane

In this paper, we experimentally asses the performance of wavelength modulation spectroscopy-based spectrometers incorporating 1.3 m-long gas absorption cells formed by an antiresonant hollow core fiber (ARHCF) and a Kagome hollow core fiber. To evaluate the discrepancies with minimum methodology error, the sensor setup was designed to test both fibers simultaneously, providing comparable measurement conditions. Ethane (C2H6) with a transition located at 2996.88 cm-1 was chosen as the target gas. The experiments showed, that due to better light guidance properties, the ARHCF-based sensor reached a minimum detection limit of 4 ppbv for 85 s integration time, which is more than two times improvement in comparison to the result obtained with the Kagome fiber. Published by Optica Publishing Group under the terms of the Creative Commons Attribution 4.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.