Germanium doped D-shaped PCF-SPR methane high sensitivity sensor

A D-shaped photonic crystal fiber doped with germanium dioxide methane gas sensor based on SPR effect is proposed. The substrate of the fiber is silicon dioxide doped with germanium dioxide, and the polished surface is used as a substrate for gold-plated and methane-sensitive membranes where the sensing area is in direct contact with methane gas. Effects of different germanium dioxide doping concentrations and the structural parameters of the photonic crystal fiber on the performance of the sensor are numerically investigated by the finite element method. Simulation results show that when the germanium dioxide doping concentration is 4.1%, the maximum sensitivity of sensor is 82 nm/% with a maximum resolution of 1.2195 × 10 –4 in the range of 0 ∼ 3.5% methane concentration. The proposed sensor not only has a simple structure, but also exhibits high sensitivity, thus the sensor has great potential in pre-warning and remote monitoring of methane gas leakage.