Efficient Partial Discharge Detection by Plasmonic Photonic Crystal Fiber Sensor With Bimetallic Grating

In this article, a new approach for optical partial discharge (PD) detection in gas-insulted systems is introduced for the first time to the best of our knowledge. The suggested sensor is based on plasmonic D-shaped photonic crystal fiber (PCF). Further, bimetallic grating structure of Ag/Au is utilized to enhance the sensor sensitivity. For light detection, methyl-red-doped poly (methyl methacrylate) polymer (MR-PMMA) is used as a sensing material for its photochromic characteristics and its fast response to visible light radiation. At resonance, good coupling occurs between the surface plasmon mode and the core guided mode. The radiated light intensity reflects the charge magnitude of the occurred PD process which can be detected by calculating the shift in the resonance wavelength of the loss spectra. The structural geometrical parameters are studied to improve the sensing performance using full vectorial finite-element method. The proposed sensor achieves high sensitivity of 667 pm/mW
$\cdot $
cm
⁻²
with a linear performance with the light intensity. Moreover, the proposed sensor has advantages of simple and compact design, fabrication feasibility, electromagnetic interference immunity, fast response, and high sensitivity relative to conventional PD detection techniques using electrical methods. The designed sensor can be also utilized for laboratory testing and it could be evolved to accomplish real-time detection of PD phenomenon in gas-insulted systems.