Wiki & Tutorial

What is Fiber Optic Pigtail?

You may wonder what’s fiber optic pigtail and what’s the difference between it and a fiber optic patch. Given their kinship, no wonder people mistake one for another. We’d like to share some common knowledge about how to differentiate them.

Figure 1: fiber pigtails

Figure 1: fiber pigtails

Define: what is fiber optic pigtail?

A fiber optic pigtail is a length of fiber cable with one end terminated with a connector and leaving the other end empty to be melted with glass fiber of another fiber cable. The side fitted with a connector is to connect with equipment, while the other side is to splice another fiber cable by fusion splicing or mechanical splicing. Fiber optic pigtails are commonly used in ODFs, splice boxes, and cross cabinets.

Splicing methods

The quality of splicing matters very much as to the attenuation value. There’re three methods of splicing.

Fusion splicing

It’s the most popular splicing method. It provides the best performance due to the lowest attenuation value, usually at 0.03 – 0.05 dB, with an experienced splicer even below 0.02 dB. Thermal fusion splicing also offers reliable durability. Usually using an electric arc, the goal is to make the splice and its surrounding region remain almost intact.

Figure 2: thermal fusion splicing

Figure 2: thermal fusion splicing

This video below shows how to fusion splice two optical fibers if you want to know more visuals.

Mechanical splicing and Adhesive splicing

These two methods are used less often due to complexity or high damping value. For mechanical splicing, the attenuation value at the splice points is usually at 0.2 – 0.5 dB, much higher compared to thermal fusion splicing.

Figure 3: mechanical splicing

Figure 3: mechanical splicing

Types of fiber pigtails

Generally, we can classify fiber pigtails in terms of several factors, such as fiber cables, fiber connector types, fiber count, applied environment, etc.

By Connector Types

LC, SC, ST, FC, MT-RJ, MTP/MPO, and E2000 fiber pigtails are named after corresponding connector types.

Also, the polish type, e.g., PC, UPC, APC, applies to fiber pigtails. The SC/APC, FC/APC, and MU/UPC pigtails are widely used.

As for further information about the fiber connector types, you could read the 25 most important types of fiber optic connectors if you’d like to.

By Fiber Types

There is single-mode and multimode fiber, and so are the fiber pigtails. You could read Fiber Mode : Single-mode VS Multimode for detailed facts about fiber type. Single-mode fiber pigtail is terminated with a single-mode fiber connector.

By Fiber Count

Simplex, duplex, 4, 6, 8, 12, 24, and 48 strand fiber pigtails are available.

By Applied Environment

As for different deploy environments, there’re three kinds of fiber pigtails, namely bare fiber, armored pigtail, and waterproof pigtail.

Armored Pigtail

This kind of pigtail has stainless steel tube inside, aiming to keep fiber free from rodents and other unanticipated injuries.

Figure 4: Armored Pigtails

Figure 4: Armored Pigtails

Waterproof Pigtail

This pigtail has an armored outdoor PE jacket and a stainless-steel intensified impermeable unit, widely used in data transmission networks and harsh environments, generally with 2, 4, 8, and 12 fiber cores.

Figure 5: Waterproof Pigtail

Figure 5: Waterproof Pigtail

By male or female version

Generally, fiber pigtails have male or female connectors, i.e., plug and jack formats.

Fiber Optic Pigtail vs. Fiber Patch Cord: What’s the difference?

People unfamiliar with fiber optic assemblies may get confused as these two resemble each other. To put it simply, we could distinguish them by appearance and kinship.

By Appearance

Pigtails have only one end preinstalled with a connector, while patch cords have both two ends preloaded with connectors. The picture below shows that one can easily identify fiber pigtails from patch cords.

Meanwhile, fiber pigtails are often unsheathed, whereas patch cords are jacketed. That’s because pigtails are normally spliced, then protected in a splice box.

Figure 6: fiber pigtails vs fiber patch cords

Figure 6: fiber pigtails vs. fiber patch cords

By Kinship

One can directly cut fiber patch cords into two pieces to make two fiber pigtails, yet you can’t do it reversely.

Why do people do this? Because on-site testing of a pigtail is complex, and factory pre-installed fiber patch cords have guaranteed its continuity and best performance. To be more convenient, people buy unsheathed patch cords after testing their performance (needless to say, they can stand the test), subsequently cutting them into two pieces to make two lengths of pigtails as you wish.

Fiber Pigtail Specifications

These parameters are generally present in fiber pigtail specifications, including fiber type (single-mode or multimode), connector type (commonly used are LC, SC, ST, FC, MPO, E2000), polish (PC, UPC, APC), the outer diameter of cable, tensile strength, operation temperature, ferrule material, insertion loss, return loss, bend radius.

Here we provide a sample of fiber pigtail specifications.

Fiber TypeSingle-modeMultimode
Polishing TypePC UPC APCPC
Insertion Loss (dB)≤0.35 (0.15 typical)<0.5 (0.25 typical)
Return Loss (dB)≥55≥25
Mating durability500
Tensile Strength200N
Safety ComplianceLSZH Grade  
Operation Temperature (℃)-40℃ ~+80℃
Ferrule MaterialZirconia Ceramic
Cable Diameter (mm)Ø0.9, Ø2.0, Ø3.0
sample: fiber pigtail specifications

Besides, if you’re concerned with fiber connector specifications, maybe you’d like to read the Fiber Optic Connector Specifications you need to know for more details.

Color Code

According to TIA-EIA-598-A, fiber pigtails are color-coded to identify individual fibers.

These specific regulations are shown below, indicating their position and color at the same time:

6White (white)
TIA-EIA-598-A color code

The color code is repeated every 12. That is to say, the color code of position 13 is blue.


What’s the advantage of fiber pigtails? Since pigtail always comes with a factory preinstalled connector at one end, the quality is guaranteed. This means it has low termination loss. Besides, one can trace the serial number to the manufacturer.

A fiber pigtail could be spliced within a few seconds with a fusion splicer, which greatly reduces the installation cost as it spares time and energy.


We’ve discussed the basic knowledge of fiber pigtails, and let’s give it an overview. Fiber pigtails are designed to be spliced with other fiber cables at one end and linked to the patch panel or equipment at the other end, enabling a quicker termination for fiber deployment, significantly reducing installation cost, and sparing your time and energy.

Related Article:

Fiber Optic Connector: The Ultimate Guide

SC LC ST FC connectors, what is the difference?  

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