Components of pigtail fiber

A fiber optic pigtail consists of a short optical fiber with a factory-terminated connector on one end, bare fiber on the other, and a protective tight buffer coating around the fiber.

Core Components

1. Optical Fiber Core and Cladding The central part of a pigtail is the optical fiber, which can be single-mode (OS2) or multimode (OM3/OM4) depending on the application. The fiber itself consists of a glass core that carries light signals and a cladding layer that reflects light back into the core to minimize signal loss and maintain total internal reflection .

2. Tight Buffer Coating Surrounding the fiber is a tight buffer, typically 0.9mm in diameter, which provides mechanical protection and makes the fiber easier to handle during splicing. The buffer also protects the fiber from physical damage and environmental stress during installation .

3. Connector One end of the pigtail is terminated with a factory-installed connector, which can be LC, SC, ST, FC, MU, or E2000. The connector ferrule is usually made of zirconia ceramic or stainless alloy, providing precise alignment for low insertion loss and high return loss. Connectors are available in UPC (Ultra Physical Contact) or APC (Angled Physical Contact) polish types .

4. Bare Fiber End The other end of the pigtail is bare fiber, designed for fusion or mechanical splicing to a trunk cable or another fiber. This allows for a permanent, low-loss connection in the field .

5. Optional Features Some pigtails are color-coded for easy identification, and multi-fiber pigtails may bundle several fibers together in a single tight-buffered cable. The fiber jacket is often omitted on the bare end to facilitate splicing, while the connector end may have a short protective boot .

Summary of Composition

• Core: Glass optical fiber (single-mode or multimode)
• Cladding: Glass layer surrounding the core
• Buffer: 0.9mm tight buffer for protection
• Connector: Factory-terminated ferrule (zirconia or stainless alloy), LC/SC/ST/FC types, UPC/APC polish
• Bare Fiber End: Exposed fiber for splicing
• Optional: Color coding, multi-fiber bundles, protective boots

This combination ensures that fiber optic pigtails provide high-performance, reliable connections while simplifying field installation and reducing signal loss.