Fiber pigtail also called fiber optic pigtail refer to a single, un-buffered optical fiber that has an optical connector on one end and a length of exposed fiber at the other end. The end of the pigtail is stripped and fusion spliced to a single fiber of multi-fiber trunk to break out the multi-fiber cable into its component fibers for connection to the end equipment. Fiber pigtails are often used in a fiber termination box, by linking the fiber optic cables to fiber converters or fiber optic transceivers to constitute a light data transmission path. Other components used in this path include optical fiber coupler, fiber patch cable etc.

Based on the fiber mode, the fiber pigtail can be divided into multimode fiber pigtails and single mode fiber pigtails. Multimode fiber pigtail is with original jacket can transmit to 500m with working wavelength of 850 nm. It is often used for short-range connectivity. Single mode is with yellow jacket, the working wavelengths are 1310nm and 1550nm and transmission distance is 10km and 40km respectively.

According to the ITU-T (International Telecommunication Union Telecommunication) standardization organization, fiber optic pigtails are categorized into Fiber pigtail that conforms to G.652 and G.653 fiber splicing technology standard. Fiber optic splicing technology is primarily to use a fiber splicing machine to fuse splice the fiber with fiber or the fiber with fiber pigtails. In this process, the bare fibers of the fiber optic cables are fuse spliced with the fiber pigtails to become a whole. With the fiber optic connector at one end of the fiber pigtails, they are connected to fiber optic transceivers, the optical fibers connected with the twisted pairs, and then connect with the information outlets. Main tools used in the fiber splicing technology include fiber termination box, fiber optic converter, fiber optic transceiver, fiber pigtail, optical fiber coupler, fiber stripper, and fiber optic cleaver, etc. Currently fiber optic pigtail with SC, ST, FC, LC MT-RJ, SC/APC, FC/APC, E2000 fiber optic connectors are available in the market.

Fiber cables need to have connectors fitted before they can attach to other equipment. Pigtails and fanout kits are two different solutions to terminate the fiber with connectors. Pigtails is generally refers to two fiber optic cable connection with is general used in the fiber termination box in the wild for fusion splicing two optical cable fibers. fanout kits is mainly used in the end of fiber optical cables when connected to the other devices, it needs a fiber pigtail accomplish the connection.