Three-core fiber-based temperature-insensitive twist sensor

We have experimentally proposed an all-fiber temperature-insensitive twist sensor, which is fabricated by splicing a three-core fiber (TCF) section and two parts of single-mode fibers (SMFs). Because of the special structure of TCF, the fundamental core mode and cladding mode can interfere with each other. The experimental results show that the maximum twist sensitivity is-0.250 nm/(rad/m) in the range of 0-50 rad/m, and 0.109 nm/(rad/m) in the range of -50-0 rad/m. The sensor has features of all-fiber structure, low-cost, easy-fabri-cated, and temperature insensitive, which makes it a competitive candidate for harsh environment sensing application.