In this guide, we'll walk you through exactly how to splice fiber without a fusion splicer, covering the tools you need, the step-by-step process, performance specs, and common mistakes to avoid. By the end, you'll be equipped to make clean, low-loss connections in any field scenario. What is a. Fiber splicing means joining two optical fibers (permanently or temporarily) such that light guided in one fiber and reaching the joint (splice) can be transferred into the second fiber with low insertion loss. Imperfect coupling means that some of the light coming from the first fiber gets into. Fiber optic cables are the invisible highways of our digital world, carrying massive amounts of data at the speed of light.