Highly sensitive magnetostrictive sensor with well-sealed and sensitivity tunability

In this article, we propose and experimentally testified a highly sensitive magnetostrictive sensor with well-sealed and sensitivity tunability. The sensor is consisted of a Terfenol-D cylinder and a fiber-optic Mach-Zehnder interferometer (MZI) affixed inside the cylinder. As an energy transducer, the Terfenol-D converts the external magnetic field into stress, which is applied to the fiber structure inside the cylinder. Here, the inside MZI is composed by symmetrical-polished plane (SPP) and inclined structure. With alternative depth of the SPP, the sensitivity tunability can be realized. The experimental results present that the sensor displays linear response to magnetic field and temperature, which adapts to simultaneous measurement. The highest magnetic field sensitivity reaches −1.113 nm/mT. Furthermore, the cylinder structure provides well-sealed property for inside sensor, which indicates actual application in future.