Interferometric fiber-optic bending/nano-displacement sensor using plastic dual-core fiber

H. Qu, G. F. Yan, M. Skorobogatiy
2014 Optics Letters  
We demonstrate an interferometric fiber-optic bending/micro-displacement sensor based on a plastic dual-core fiber with one end coated with a silver mirror. The two fiber cores are first excited with the same laser beam, the light in each core is then back-reflected at the mirror-coated fiber-end, and, finally, the light from the two cores is made to interfere at the coupling end. Bending of the fiber leads to shifting interference fringes that can be interrogated with a slit and a single
more » ... etector. We find experimentally that the resolution of our bending sensor is ~3x10-4 m-1 for sensing of bending curvature, as well as ~70 nm for sensing of displacement of the fiber tip. We demonstrate operation of our sensor using two examples. One is weighting of the individual micro-crystals of salt, while the other one is monitoring dynamics of isopropanol evaporation.
doi:10.1364/ol.39.004835 pmid:25121887 fatcat:n4ckf6ewlvaodo5iueui5lexri