D1-3.1 - Temperature-Compensated Hydrogen Sensing with In-Fiber Dual-FBG Fabry-Pérot Structures and Palladium-Based Thin Films

Event

23. ITG/GMA-Fachtagung Sensoren und Messsysteme 2026
2026-06-09 - 2026-06-10
Nürnberg

Band

Vorträge

Chapter

Gassensoren

Author(s)

A. Braunmüller, F. Buchfellner, J. Roths - Munich University of Applied Sciences, Munich, M. Becherer - Technical University of Munich, Munich

Pages

168 - 173

DOI

10.5162/sensoren2026/D1-3.1

ISBN

978-3-910600-11-9

Price

free

Abstract

Hydrogen sensors based on in-fiber dual-FBG Fabry-Pérot (FP) structures present an advanced sensor platform with the ability to achieve a highly precise detection of hydrogen and temperature. By selectively covering the cavity formed between two UV imprinted Bragg reflectors with a Pd₈₀:Au₂₀ nanofilm provides the sensor with the potential for simultaneous measurements of temperature and hydrogen concentration in a single optical fiber and sensor element. For this purpose, current efforts aim for decoupling the sensor response in regard of temperature and hydrogen-induced strain by applying a fully zero-point referenced sensor calibration scheme. This work addresses the fabrication of such a dual-FBG FP sensor under consideration of suitable design parameters and its subsequent calibration. For the latter, the determination and compensation of the intrinsic temperature response of the sensor will be demonstrated on the example of measurements of H₂ concentrations between 10⁰ and 20,000 ppm at temperatures of 30°C and 50°C. This compensation substantially reduces the cross-sensitivity of the sensor regarding temperature- and hydrogen-induced wavelength shifts. Above all, however, the results obtained with this sensor configuration show hydrogen measurements free of hysteresis with the capability to extend for multi-point sensor probes by wavelength division multiplexing.