Fiber optic cleaver is used to cut the fiberglass to make a good end face, as we know the quality of the bare fiber end face will determine the quality of the joint of the fibers in the fiber optic fusion process, and the joint point quality means higher or lower attenuation of the fiber connection line.
An optical fiber is cleaved by applying a sufficient high tensile stress in the vicinity of a sufficiently large surface crack, which then rapidly expands across the cross section at the sonic velocity.This idea has many different practical implementations in a variety of commercial cleaving equipment. Some cleavers apply a tensile stress to the fiber while scratching the its surface with a very hard scribing tool, usually a diamond edge.
Fiber optic cleavers are used in fusion splicing to make the ready to use optical fiber before putting them into the fusion splicer to melt them together. Some cleavers scratch the surface first, and then apply tensile stress, and some apply a tensile stress that is uniform across the cross section while others bend the fiber through a tight radius, producing high tensile stresses on the outside of the bend.
Commercial instruments for simultaneously cleaving all the fibers in a ribbon are also widely available. These ribbon cleavers operate on the same principles as single fiber cleavers. The average cleave quality of a ribbon cleaver is somewhat interior to that of a single fiber cleaver. Scribe-and-break cleaving can be done by hand or by tools that range from relatively inexpensive hand tools to elaborate automated bench tools. Any technique or tools is capable of good cleaves; the trick is consistent finishes time and time again.