Multiplexed optical fiber extrinsic Fabry-Perot interferometric sensor system

Abstract

In this paper, a multiplexed optical fiber extrinsic Fabry-Perot interferometric (EFPI) sensor system with optical switch is implemented. To obtain the absolute length of the EFPI air gap, a cross-correlation signal processing method is introduced. The multiplexing of the sensors is basically based on a 1×N optical switch directly connected to a N-element EFPI sensor array. The EFPI sensors are interrogated one after the other with the same spectrometer by activating the corresponding channel of the optical switch. A multiplexed sensor system prototype with two EFPI sensors is demonstrated to verify the performance of the multiplexing method.