A splice crew reaches site, opens the box and finds SC/UPC pigtails where the patch panel takes LC/APC. The job stops, a re-order goes out, and a day is lost.…
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A splice crew reaches site, opens the box and finds SC/UPC pigtails where the patch panel takes LC/APC. The job stops, a re-order goes out, and a day is lost. Fiber pigtails are among the cheapest parts of a network, yet ordering the wrong one is one of the most common causes of delay. This guide explains what a pigtail is, the options that matter and how to order the right one first time.
What is a fiber pigtail?
A fiber pigtail is a short length of optical fiber with a factory-fitted connector on one end and bare fiber on the other. The bare end is fusion spliced onto the incoming cable, usually inside an FMS, ODF, joint closure or FAT box. The connector end then plugs into an adaptor, giving the network a clean, tested termination point.
Factory termination is the reason pigtails exist. Polishing a connector in the field is slow and inconsistent; splicing a factory-polished pigtail gives low, predictable loss in a fraction of the time.
Pigtail connector types
The connector on the pigtail must match the adaptor it will plug into.
| Connector | Where you’ll usually find it |
| LC | High-density panels, FMS, data centres, newer FTTH equipment |
| SC | FTTH distribution, FAT boxes, wall outlet boxes, ODFs |
| FC | Test equipment, older telecom and CATV installations |
| ST | Legacy enterprise and campus networks |
| E2000 | Carrier and broadcast networks that want a shuttered, self-closing connector |
LC pigtails and SC pigtails cover most new FTTH and telecom builds in India. For a deeper comparison of the connectors themselves, see our buyer’s guide to optical fiber connectors.
UPC vs APC polish
The end face of the connector is polished in one of two ways:
- UPC (Ultra Physical Contact): a flat, slightly domed end face. Connector bodies are usually blue.
- APC (Angled Physical Contact): the end face is polished at an 8-degree angle, so reflected light escapes into the cladding instead of travelling back down the fiber. Connector bodies are green.
APC gives much lower back reflection, which is why it is the norm in PON-based FTTH and video overlay networks. UPC is common in Ethernet and data links. The rule is simple: never mate APC with UPC. The angled and flat faces do not meet properly, causing high loss and possible damage to both end faces.
Single mode vs multimode
- Single mode (OS2, 9/125 µm): used for FTTH, access and long-distance telecom links. Jackets are usually yellow. An LC pigtail single mode or SC pigtail single mode is what most telecom projects order.
- Multimode (OM1 to OM5, 50/125 or 62.5/125 µm): used for short links inside buildings and data centres. OM3 and OM4 jackets are usually aqua.
Mixing the two in one link causes heavy loss, so the pigtail must match the cable it is spliced to.
Indoor vs outdoor pigtails
Standard indoor pigtails have a 0.9 mm tight-buffered fiber, sometimes in a 2 mm or 3 mm jacket. They are designed to live inside a closure, tray or rack.
Waterproof outdoor pigtails use a tougher, sealed jacket and connector body so they can be routed outside an enclosure, for example from a pole-mounted box to a radio unit. Choose by where the connector will sit, not where the cable runs.
Simplex, duplex and bundled pigtails
Most FTTH work uses simplex pigtails, one fiber per pigtail. Duplex pigtails carry two fibers for transmit and receive pairs. For high-count splicing, colour-coded 6, 12 or 24 fiber bundles save time and keep fiber order clear inside the FMS.
Ordering checklist
Before you raise a purchase order for OFC pigtails, confirm these six points:
- Connector type: LC, SC, FC, ST or E2000.
- Polish: UPC or APC, matched to the adaptor and network design.
- Fiber type: single mode OS2, or the right multimode grade.
- Length: 1.5 m is common; allow enough slack for splice trays.
- Buffer and jacket: 0.9 mm, 2 mm or 3 mm, indoor or waterproof outdoor.
- Test report: insertion loss and return loss figures for each pigtail.
Frequently asked questions
What is the difference between a pigtail and a patch cord? A pigtail has a connector on one end and is spliced on the other. A patch cord has connectors on both ends and links two ports. Read more in Patch Cord vs Pigtail.
Can I use a UPC pigtail in an APC adaptor? No. Mating UPC and APC end faces causes high loss and can damage the connectors. Match the polish across the whole link.
Which pigtail is used in FTTH? Most FTTH networks use single mode SC/APC or LC/APC pigtails, chosen to match the splitters and adaptors in the FAT box and FMS.
Why is the APC connector green? Green is the industry colour code for angled polish, so technicians can tell APC from UPC at a glance.
Order the right pigtail first time
Byteworx supplies indoor and waterproof outdoor fiber pigtails for FTTH and telecom projects. Browse the range on our patch cord and pigtails page, or contact our team with your connector, polish and length, and we’ll match it to your project.