Learn how to splice fiber optic cable using fusion splicing with this complete step-by-step guide. Includes tools, best practices, loss standards (ITU-T G. 652), cost analysis, and FAQs for network engineers and installers. Splicing is typically required during cable installation, maintenance, or network expansion. In this comprehensive guide. A fiber optic cable splice is the process of permanently joining two fiber optic cables to create a continuous light path—vital when cables are cut, damaged, or need extending. Fiber optic strands are ultra-lightweight and about as thin as human hair, and yet, they have more than eight times the pulling tension of a copper wire.