Types of Optical Fiber Cable: Construction, Tubes and Installation Methods

Types of Optical Fiber Cable: Construction, Tubes and Installation Methods

Posted on July 07, 2026

“Optical fiber cable” covers a family of designs that differ in tube structure, fibre count, protection and how they’re installed. Picking the right type controls both performance and cost. This guide classifies the main types of optical fiber cable Systematic manufactures. For specific spec values, see the optical fiber cable specifications guide.

By tube structure: uni-tube vs multi-tube

Type	Construction and fibre count
Uni-tube cable	A single central loose tube holding up to 12 fibres; compact, lower-cost, common for access/distribution.
Multi-tube (loose-tube) cable	Multiple loose tubes (with jelly) S-Z stranded around a non-metallic FRP central strength member; up to 144 fibres for backbone routes.

By armouring: armoured vs unarmoured

•     Unarmoured — lighter and flexible, for blowing into HDPE ducts or PVC pipes where the duct provides mechanical protection.

•     Armoured — adds a protective layer for direct-buried or rodent-prone routes and higher crush resistance.

By installation method

•     Duct cable — designed to be pulled or blown into service ducts; glass-yarn or aramid-yarn reinforcement adds axial pulling strength.

•     Aerial cable — strung between poles for CATV and distribution networks.

•     Direct-buried — armoured construction laid directly in trench.

Single-mode vs multimode (fibre type)

Independent of cable construction, the fibre itself is either single-mode (long-distance, telecom backbone, G.652/G.657 class) or multimode (shorter campus/data-centre runs). Most outside-plant OFC uses single-mode fibre. For a copper comparison, see OFC vs copper cables.

Jacketing options

Outer jacket material is selected for the environment: HDPE (general outdoor/duct), LSZH (low-smoke zero-halogen for indoor/tunnels), PVC, or PA-12. Dry-core construction is available as an alternative to jelly-filled tubes.

Not sure which type fits your route? Read the comprehensive OFC guide or talk to Systematic.

Frequently Asked Questions

What is the difference between uni-tube and multi-tube cable?

A uni-tube cable has a single central tube (up to 12 fibres); a multi-tube cable has several loose tubes stranded around a central FRP member, scaling up to 144 fibres for backbone use.

When should I use armoured optical fiber cable?

Use armoured cable for direct-buried routes, rodent-prone areas, or anywhere needing higher crush resistance. Unarmoured cable is fine when blown into protective ducts.

How many fibres can an optical fiber cable hold?

Systematic’s designs range from up to 12 fibres in uni-tube cables to up to 144 fibres in multi-tube constructions. See the specifications guide.

Is single-mode or multimode better?

Single-mode suits long-distance telecom and backbone links; multimode suits shorter campus and data-centre runs. The choice depends on distance and equipment, not the cable jacket.