Intrinsically Safe Optical Fiber Hydrogen Sensor Using Pt-SiO₂ Coated Long-Period Fiber Grating

Hydrogen, a promising clean energy carrier, needs safe detection due to its flammability. Conventional electrical hydrogen sensors have drawbacks like high operating temperatures, poor selectivity and ignition risks. We propose an optical sensor using long-period fiber gratings (LPGs) coated with Pt-SiO₂ nanomaterials. It works via catalytic reaction: H₂ reacts with O₂ on Pt nanoparticles, releasing heat that shifts LPG's resonant wavelength. Structural characterization showed porous SiO₂ with uniform Pt, ensuring efficiency and stability. Experiments proved it sensitively responds to 0.5-2.5% H₂ (max wavelength shift 7.544 nm), with fast response/recovery, good repeatability/reversibility. Logistic fitting (R² = 0.999) confirmed strong correlation. This sensor, safe, sensitive and stable, has great potential for real-time H₂ monitoring in critical environments.