Sensitivity enhancement of interferometric fiber-optic accelerometers using multi-core fiber

We propose and demonstrate a novel method for improving the sensitivity of fiber-optic interferometric accelerometers based on multi-core fiber space division multiplexing technology. In this method, MCF is used to replace the single-mode fiber as the sample arm of the conventional interferometers. MCF and a pair of fan-in/fan-out devices are used to build a Mach-Zehnder interferometric accelerometer to experimentally demonstrate the sensitivity enhancement. The proposed accelerometer has a working frequency bandwidth from 0.5 Hz to 90 Hz, and achieves a 5-fold sensitivity enhancement from 191.15 rad/g for single-core to 965.25 rad/g at 80 Hz. The multicore fiber solution can be an universal method to enhance acceleration sensitivity of all interferometric accelerometers. Moreover, the same sensitivity of the sensors can be achieved by using shorter length of MCF, which can further reduce the size of three-components accelerometers.