2025 International Conference on Sensing, Measurement & Data Analytics in the era of Artificial Intelligence (ICSMD 2025)

We present a compact Fabry–Perot fiber-optic hydrogen sensor employing a palladium-decorated hexagonal boron nitride (Pd/hBN) film as the reflective membrane. The nanometer-thick hBN substrate offers high mechanical strength and low thermal expansion, enabling efficient transduction of Pd lattice expansion into optical wavelength shifts. The sensor achieves a sensitivity of 0.58 pm/ppm over a hydrogen volume fraction range of 0.02 %–0.50 %, with a response time of 60 s at 0.10 % H₂ and excellent repeatability without response memory. The proposed design combines high sensitivity, fast response, and structural robustness, which demonstrates strong potential for real-time hydrogen monitoring in harsh environments such as transformer oil.

fiber-optic sensor, hydrogen detection, hexagonal boron nitride, online monitoring