Fiber sensor tracks 3D shapes with tiny, laser-cut parts

A reel-to-reel femtosecond laser writing process now enables the creation of three-dimensional shape sensors within standard single-mode optical fibers. Researchers densely inscribed “misplaced orthogonal eccentric scatterers,” or MOESs, into the cladding of these fibers, a location distinct from the core, to build a miniaturized system for high-precision shape detection. Each MOES element acts as a curvature-dependent light scatterer, spatially encoding 3D deformation information. The intensity-domain reconstruction algorithm also exhibits strong immunity to environmental perturbations, opening possibilities for fiber sensors in unstructured and dynamic environments. A manufacturing process utilizing a continuous, moving fiber allows for the dense creation of three-dimensional shape sensors, avoiding the painstaking assembly typically associated with high-precision instrumentation. Researchers detailed a “reel-to-reel femtosecond laser writing process” capable of fabricating arrays of uniquely designed structures within optical fibers, offering a pathway to scalable and potentially lower-cost…