End face preparation of large core optical fibers is essential to obtain best transmission performances particularly when high optical power is injected into the fiber.
The best transparency is obtained by cleaving the fiber as opposed to polishing where small scratches always remain. However most of the cleaving tools have been developed for telecom fibers and are not adapted to cleaving large core fibers.
SEDI-ATI Fibres Optiques was among the first to propose the “Infocut” tool able to cleave fibers up to 1000µm. A complete re-design of this tool is now proposed under the name of “I.Cleave” with a number of improvements. It is considerably more user friendly and able to cleave fibers up to 1500µm with perpendicularity better than 1 degree.
The principle is to make a notch on the fiber silica surface with a diamond blade then apply traction along the fiber axis until it cleaves. The traction system is designed so that no flexion or torsion is applied to the fiber and also to provide a very progressive movement thanks to a screw mechanism. The tool is very versatile and can be adjusted to cleave most fibers including polyimide coated fibers.