Aperiodic multi-core fibers for lens-less endoscopy

Abstract

Lens-less endoscopy based on multi-core fibers (MCFs) with aperiodic core arrangements enables 3D imaging deep inside tissue with reduced imaging artifacts such as higher-order diffraction. With a scalable iterative stack-and-draw process, we fabricated and characterized (e.g. cross-talk) two aperiodic MCFs: (i) a 250 µm fiber with 420 cores and (ii) a 333 µm fiber with 1281 cores. Since lens-less endoscopy is sensitive to dynamic bending, two different approaches to twist the fibers were evaluated: i) rotation of the fiber preform during fiber drawing and (ii) post-production twisting of the MCF within a fiber processing station.