Investigation of scattered-bend loss coupling in Polymer Optical Fiber (POP) - based displacement measurement sensor

This work proposes a displacement sensor based on the coupling of scattering loss during fiber bending by using a multimode polymer optical fiber. To couple the radiated light from scattered loss produced by bending, this work employed a twisted structure comprising two fibers. The experiment employed two polymer optical fibers that had been twisted and bent. The bent radius grows smaller as the fiber draughts. The scattered-bend loss increases from illuminated fiber and coupled out to the receiving fiber. Static measurement testing is done and has a range of roughly 160 mm with a sensitivity of 0.817 nW/mm, a resolution of 1.228 mm, and a repeatability error of 1.856 %. The sensor exhibits high linearity from 0 to 80 mm. The sensor's design structure and analysis are simple, comprehensive, and cost-effective, with potential benefits in industrial applications.