We propose a simplified common-path autocorrelator based on Fizeau interferometer for quasi-distributed measurement. A four-port fiber circulator is employed to connect broadband light source, fiber sensor array, Fizeau interferometer and photodetector, constructing a most simple configuration and common-path between sensing and reference signals. This common-path configuration of the autocorrelator can greatly reduce the polarization and dispersion mismatch between sensing and reference signals. The use of circulator can also avoid reflective light from sensor array reentering into light source, which can improve the stability and efficiency of the autocorrelator. The optimization of the autocorrelator is theoretically discussed, and a seven-sensor autocorrelator is experimentally demonstrated. The common-path sensing system is quite suitable for quasi-distributed measurement of strain and temperature in smart structures.

Date Published: 17 May 2011
PDF: 4 pages
Proc. SPIE 7753, 21st International Conference on Optical Fiber Sensors, 77531W (17 May 2011); doi: 10.1117/12.885658

Published in SPIE Proceedings Vol. 7753:
21st International Conference on Optical Fiber Sensors
Jacques Albert; Wojtek J. Bock, Editor(s)