Authors: Y. Sun, G. Feng, G. Georgiou, I. Padron, E. Niver, K. Noe and K.K. Chin
Affilation: New Jersey Institute of Technology, United States
Pages: 229 - 232
Keywords: Fabry Perot, acoustic, sensor, fiber optic, MEMS, partial discharge
The diaphragm fiber optic sensor (DFOS) solely based on Fabry-Perot has been designed and fabricated with Micro-electric mechanical system(MEMS) technology. The DFOS utilizes a diaphragm as the sensing element to detect static and dynamic pressure (acoustic wave). The fiber is used to deliver the steady probing light and to receive the reflected light modulated by signals under detection1-4. The silicon diaphragm with embossed center was design with a gap width kept accurately at 2 to 5 µm. A special MEMS method in the processing of the silicon diaphragm was developed. The diaphragm –fiber angular misalignment maintained at less than 0.1?. The DFOS meets the criterion set forth in the static pressure test and therefore is truly Fabry-Perot. Currently an imminent application of DFOS is partial discharge (PD) acoustic detection in high voltage transformers in the power industry. PD within the power transformer could lead to degradation of the insulation system and may therefore result in the catastrophic failure of the power grid. Our Fabry-Perot DFOS has demonstrated excellent performances in on-line monitoring of Partial Discharge in power transformers, exhibiting high sensitivity, wide dynamic range, and high signal-to-noise ratio. Its superior sensing capacities, small size , low cost, versatility, and potential for multiplexing and integration may lead to a broad range of applications.