Using Pd/WO3 composite thin films as sensing materials for optical fiber hydrogen sensors

In this article, a fiber-optic hydrogen gas sensor using composite palladium and tungsten trioxide (WO3) was proposed and characterized. By magnetron co-sputtering process, Pd/WO3 composite thin films were deposited on end surface of a single-mode fiber (SMF) and a side-etched multimode fiber (MMF). Modulation of optical power intensity is observed with different hydrogen concentrations. Due to its different sensing principle and structure, improvement of hydrogen sensing response and mechanical stability is reported.