Design Optimization of Pd-Coated Side-Polished Single Mode Optical Fiber Hydrogen Sensors

Palladium (Pd)-based optical fiber sensors exhibit large sensitivity to detect hydrogen. We performed design study on Pd-coated side-polished optical fiber sensors using modal approach. The presence of buffer layer (i.e., the remaining cladding or other material) between core of the side polished single mode fiber and hydrogen absorbing Pd layer shows a strong effect on sensitivity. The thickness of buffer and Pd layers are optimized to achieve higher sensitivity. Use of different materials as buffer layer has been explored and we observed that teflon gives maximum sensitivity.