Fiber layout sensing with one single-core standard single-mode fiber

Fiber shape sensing is a fascinating field that has been gaining attention over the past decade. However, its widespread utilization is hindered by the requirement of complex detection systems connected to either several cores in a multi-core fiber, or to multiple single-core fibers. In this work, we propose a technique able to recover fiber shape information, such as wounded and straight segments, using only one single-core standard single-mode fiber, thus realizing the first fiber layout sensor. This is achieved by exploring distributed fiber sensors from a different perspective: rather than making use of known fiber properties to measure environmental perturbations, we take advantage of weak and random acoustic perturbations to measure fiber properties. As the same acoustic noise is perceived for fiber segments spatially close, their high correlation indicates the proximity of fiber segments, which enables the recovery of the fiber layout. Proof of concept experiments were realized, successfully identifying circular loops, straight paths, and fiber spools. Although a complete three-dimensional reconstruction of the fiber’s shape is currently unfeasible, the technique’s simplicity and its seamless integration with standard single-core fibers pave the way for a new class of fiber sensors.