Pigtail, also known as pigtail, has only one end with a connector, and the other end is a broken end of a fiber optic cable core. It often appears in fiber optic terminal boxes. Executive Summary: A fiber optic pigtail is one of the most commonly specified yet least understood components in structured cabling. Get the wrong connector type, the wrong polish, or skip proper fusion splicing technique—and you're looking at elevated signal loss, increased back reflection, and a. Fiber pigtails are simple in appearance, yet essential in function. They are the bridge between fiber optic cables in the field and the equipment or patch panels that manage them.