Journal: Sensors
Paper: Gas Sensor Based on Photonic Crystal Fibres in the 2v₃ and v₂ + 2v₃ Vibrational Bands of Methane

AUTHORS: Ana M. Cubillas, Jose M. Lazaro, Olga M. Conde, Marco N. Petrovich, José M. López-Higuera
Abstracts:
In this work, methane detection is performed on the 2v₃ and v₂ + 2v₃ absorption bands in the Near-Infrared (NIR) wavelength region using an all-fibre optical sensor. Hollowcore photonic bandgap fibres (HC-PBFs) are employed as gas cells due to their compactness, good integrability in optical systems and feasibility of long interaction lengths with gases. Sensing in the 2v₃ band of methane is demonstrated to achieve a detection limit one order of magnitude better than that of the v₂ + 2v₃ band. Finally, the filling time of a HC-PBF is demonstrated to be dependent on the fibre length and geometry.