Simultaneous Ultrasound and Ultraviolet Radiation Measurement Based on Fabry–Pérot Interference and Fluorescence for Partial Discharge Detection

A novel optical fiber sensor that simultaneously measures ultrasound and ultraviolet (UV) radiation was proposed for partial discharge (PD) detection, which is based on Fabry-Pérot interference (FPI) and fluorescence properties. The proposed sensor adopts a Fabry-Pérot structure consisting of a grooved diaphragm and a cerium and terbium co-doped fluorescent (CTDF) fiber. This design employs the grooved diaphragm-based FPI for ultrasound detection, while the lead-in CTDF fiber is specifically utilized for UV radiation detection, minimizing cross-sensitivity between the two due to the distinct detection mechanisms. The parameters of the grooved diaphragm were determined by finite element method simulation to precisely tune the resonance frequency of the proposed sensor, ensuring that the proposed sensor meets the sensitivity requirements for effective PD ultrasound detection. Experimental results demonstrate that the proposed sensor is capable of measuring both ultrasound and UV radiation simultaneously, with an ultrasound pressure sensitivity of 23.14 mV/Pa at 34.4 kHz and a UV response sensitivity of 104 mV/(μWꞏcm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-2</sup>) at 365 nm wavelength. With its compact size, inherent insulation properties, and electromagnetic interference resistance, the proposed sensor can be directly installed within high-voltage equipment, demonstrating the significant potential for a wide range of applications in PD detection.