Distributed UV Light Sensor Probe Based on Photo-Responsive Polymer Coated Optical Fiber

A novel distributed ultraviolet (UV) light sensor based on a functional polymer-coated optical fiber is proposed. An azobenzene polymer was prepared by mixing an azobenzene compound and UV curing agent and applied as coating on a distributed strain sensor probe as optical fiber using the UV curing process. This coating was reversibly stretched by the UV light, and in the coated region, it induced tensile strains by the UV light along the fiber. This strain, measured by a distributed fiber optic sensor (DFOS) interrogator, was up to 124.5 με under a UV power of 10 mW/cm
²
. Using this method, distributed UV monitoring can be realized in conventional strain/temperature DFOS interrogators.