Hydrogen leak detection: a comparison between fiber optic sensors based on different designs.

We present a review of optical fiber hydrogen sensors based on Palladium. Palladium hydrogen optical fiber sensing system can be considered as a model for other metal hybrid system. Besides, the Palladium hydrogen, systems are well characterized in bulk, cluster or thin film form. We focus on the fiber principles. We discuss then their performances regarding their configurations. We will conclude by introducing the challenges for designing an ideal hydrogen optical fiber sensor based on metal hybrids approach and which designing direction seen the best to take.