Data-dependent system approach for strain measurement in interferometric fiber optic sensor

A fiber optic interferometric sensor (Mach-Zehnder type) based on data-dependent system is presented for strain measurement. The interferogram recorded from the interferometer has been digitized and characterized by means of an autoregressive model. The phase change due to the measurand has been obtained from the self coherence function of the interferogram. The modulation of group delay and dispersion are obtained from the phase curve. Results for applied strain in the range of 5-10 mu strain are presented. (C) 2003 Elsevier Ltd. All rights reserved.