A short length of optical fiber that is permanently affixed to an active device, e. G. , LED or laser diode, and is used to couple the device, using a splice or connector, to a longer fiber. 2. A short length of single-fiber cable, usually tight-buffered, that has an optical connector on one end and a length of exposed fiber at the other end. Note: The exposed fiber of the pigtail is then spliced to one fiber of a multifiber trunk, i.e., arterial, cable, to enable the multifiber cable to be "broken out" into individual single-fiber cables that may be connected to a patch panel or an input or output port of an optical receiver or transmitter. 3. A short length of electrical conductor permanently affixed to a component, used to connect the component to another conductor.