Design and performance of a mechanical strain optical sensor using a multimode fiber locally stressed by a periodical micrometric perturbation

摘要

We present a new kind of intrinsic intensity modulation optical fiber sensor. The sensitive effect is obtained by a mechanical perturbation of the fiber at the micrometric scale. The fiber diameter and the refractive indices are locally modified. The principle of this sensor is a losses modulation in this perturbed zone of the fiber due to different physical effects like thermo-optic or elasto-optic effects. The perturbation is obtained by clipping the fiber in two microstructured jaws. Mechanical and electromagnetic simulations are used to predict the response of the sensor. A strain test on the sensor is compared to the modeling.