Multiplexed Fiber Optic Twin-sensor Array based on a Combination of Mach-Zehnder and Michelson Interferometers

A multiplexed white light interferometric fiber optic twin-sensor array is designed and demonstrated. In this sensing system, based on a combination of Mach-Zehnder and Michelson interferometers, an optical path matching technique is used to demodulate each twin sensor. The twin-sensor array consists of 2 × N sensing elements linked by a 3 dB coupler. While one of the twin sensors is used to measure strain, the other one compensates the variation caused by the temperature. The multiplexing capacity of the sensing scheme is analyzed and an experimental result with a 2 × 3 twin-sensor array is demonstrated and tested.