A diaphragm-based interferometric fiber optic sensor that uses a low-coherence light source was designed and tested for on-line detection of the acoustic waves generated by partial discharges inside high-voltage power transformers. The sensor uses a fused-silica diaphragm and a single-mode optical fiber encapsulated in a fused-silica glass tube to form an extrinsic Fabry-Perot interferometer, which is interrogated by low-coherence light. Test results indicate that these fiber optic acoustic sensors are capable of faithfully detecting acoustic signals propagating inside transformer oil with high sensitivity and wide bandwidth.
© 2003 Optical Society of America
(060.2370) Fiber optics and optical communications : Fiber optics sensors
(120.1880) Instrumentation, measurement, and metrology : Detection
(120.2230) Instrumentation, measurement, and metrology : Fabry-Perot
Bing Yu, Dae Woong Kim, Jiangdong Deng, Hai Xiao, and Anbo Wang, "Fiber Fabry-Perot Sensors for Detection of Partial Discharges in Power Transformers," Appl. Opt. 42, 3241-3250 (2003)