In order to demodulate frequency division multiplexed optical fiber Fabry-Perot sensors with high accuracy and absolute cavity length, an improved cross-correlation method was presented. As the applying of a special correlating factor in it, the cross correlation function at every sensor's cavity length is a single peak and multiplexed sensors that cavity length is close to each other can be easily distinguished, and segment golden search method was employed to reduce computation and demodulating speed is fast. The multiplexing experiment of two sensors was accomplished with the help of general demodulating system constituted by broadband light source, spectrometer etc. The results showed that the system can demodulate the frequency division multiplexed signal of optical fiber Fabry-Perot sensors, and the least cavity length difference that can be distinguished among multiplexed sensors is less than 6μm and fluctuation of the cavity length is less than 0.073%.

Date Published: 14 February 2005
PDF: 5 pages
Proc. SPIE 5634, Advanced Sensor Systems and Applications II, (14 February 2005); doi: 10.1117/12.572795

Published in SPIE Proceedings Vol. 5634:
Advanced Sensor Systems and Applications II
Yun-Jiang Rao; Osuk Y. Kwon; Gang-Ding Peng, Editor(s)