Effect of Metal Oxide Layers on the Performance of Polymer Optical Fiber-based Hydrogen Sulfide Sensors

This work presents the development of polymer optical fiber (POF) sensors for hydrogen sulfide $(\mathrm{H}_{2}\mathrm{S})$ detection, coated with varying numbers of metal oxide layers. Four sensors with identical structures were fabricated, and their performance was evaluated when exposed to 200 ppm of $\mathrm{H}_{2}\mathrm{S}$. Increasing the number of $\text{Fe}3\mathrm{O}_{4}$ layers led to a sensitivity enhancement, up to 8 times greater with 21 layers compared to 3 layers. However, sensitivity decreased with more than 21 layers. These findings highlight the importance of optimizing the number of layers to achieve the best performance of an $\mathrm{H}_{2}\mathrm{S}$ sensor.