A Strain Sensor Realized with Multicore Fiber Interferometer Based on Microwave Photonics with Phase Demodulation

A strain optical fiber sensor realized with multicore fiber interferometer is proposed and experimentally demonstrated based on microwave photonics with phase demodulation. Experimental results demonstrate that the sensor offers high resolution and fast response time as fast as milliseconds, achieving a linear fitting sensitivity of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-0.2293 \text{deg} / \mu \varepsilon$</tex> with an <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$R$</tex>-squared value of 0.9998.