Ultra-high sensitivity optical fiber Vernier photothermal sensor based on WTe 2

In this paper, a novel Vernier photo-thermal optical fiber sensor based on WTe 2 is proposed. The sensor is composed of a single-sided gold-plated silicon wafer and a single-mode optical fiber, and is encapsulated with a capillary tube. The air cavity and the silicon wafer cavity are cascaded to have an optical Vernier effect, and the sensitivity can be selected by adjusting the length of the air cavity. The ultra-high sensitivity of 2.53 nm mW −1 has been obtained through experiments, which has certain potential in the fields of optical imaging, detection, and sensing.