@inproceedings{373ec642d95948fa84e01091015bcb48,
title = "Hydrogen sensor based on hollow-core fiber photothermal spectroscopy",
abstract = "We report an optical fiber hydrogen sensor utilizing the photothermal spectroscopy within a hollow-core fiber, specifically targeting the 2121.8-nm quadrupole absorption line of hydrogen. Experiments demonstrate that the optical fiber sensor can detect hydrogen gas at the concentration level of 77 ppm when the lock-in time constant is 1 second. The optimal integration time is determined to be around 1867 seconds corresponding to a noise equivalent concentration of 7.2-ppm hydrogen. Importantly, we discover an intriguing phenomenon that, at higher concentrations, photothermal signal decreases with the increase of hydrogen concentration. Thermal dynamics analysis and numerical simulations indicate that the phenomenon arises from the combined effects of molecular collisional relaxation, thermal conduction process and thermo-optic effects of gas materials inside the hollow-core optical fiber.",
keywords = "gas sensor, hollow-core fiber, Hydrogen sensor, optical fiber sensor, photothermal spectroscopy",
author = "Shiyu Zhang and Shoulin Jiang and Shuangxiang Zhao and Hanyu Liao and Yuncai Wang and Yuwen Qin and Zhang, \{A. Ping\} and Wei Jin",
note = "Publisher Copyright: {\textcopyright} COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.; 29th International Conference on Optical Fiber Sensors ; Conference date: 25-05-2025 Through 30-05-2025",
year = "2025",
month = may,
doi = "10.1117/12.3061589",
language = "English",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
pages = "1--4",
editor = "Santos, \{Jose Luis\} and Sainz, \{Manuel Lopez-Amo\} and Tong Sun",
booktitle = "29th International Conference on Optical Fiber Sensors",
address = "United States",
}