Fiber cables

General information about fiber cables

Construction and application

Fiber cables are used for data transfer; serial communication, network, audio/video. Since fiber cables are made of nonconductive material, they do not transfer tension between the devices, they are therefore suitable in industry and as insulators for protection against lightning and other overvoltages.

There are two types of fiber cable for data communication: single mode and multimode.Both are made of transparent glass. Multimode cable typically reaches distances of up to 2 km while singlemode offers the largest distances between 10 and 100 km.

The difference between singlemode and multimode is the thickness of the core. It is the thickness of the core that determines whether the cable is a multi or single mode. Multi-core cable core is typically between 50μm and 62.5μm and singlemode cables are typically around 9μm. Multimode is called OM1 at 62.5 / 125 and OM3 or OM4 at 50/125. Singlemode is called OS1. See further description on the next page.

Cladding

Outside the core is a relatively thick insulation material called cladding (can be translated with "clothing") that acts as a mirror and holds the light inside the core. Outside is the buffer that protects the cladding. Then comes a layer of aramid fiber wire that adds the cable additional strength and ensures flexibility. Finally, one or more jackets will appear depending on whether the cable is used indoors or outdoors. 

μm

50/125 means that the core is 50μm and the cladding is 125μm thick. Multimode cable type OM3 and OM4

62.5 / 125 means that the core is 62.5μm and the cladding is 125μm thick. Multimode cable type OM19/125 means that the core is 9μm and the cladding is 125μm thick. Single-mode cable type OS1
The outer diameter of the cable itself depends on the application. A patch cable is thinner than a grounding cable, as the latter is further protected against rodent and moisture. The Aramid fiber is a kevlar-like fiber material that is extremely flexible and strong.

Common fiber optic:

LC (out of 1 cm mark). Approximately 11 mm wide for a duplex connector.
Also seen as simplexadapter. SC (out of 4 cm mark). Looks like LC in construction and is often confused with this, but is somewhat larger: Approx. 21 mm wide for a duplex connector
MTRJ connector (out of 7 cm mark). The connector is always duplex and can not be separated as LC and SC
ST (out of 10 cm mark) is a bayonet type plug.

Differences between Single-and Multi-mode

In single mode, the light is sent more directly, why the range is greater. Single-mode fiber cables are available in 3 different polishing qualities and multimode fiber cables in 2 different polishing qualities. Polishing methods are called PC, UPC or APC. It is not possible to discern the different polishing methods, so in order to make it visible, the standard PC version the jack is black, and for UPC the jacket is blue and for APC that the jacket is green. PC is the one with the biggest loss, UPC is with medium loss and APC with the least loss. Multimode is available only as either PC or UPC, while singlemode is available in all 3 versions. DANBIT A/S stores both single-mode and multimode as PC versions, but the other types can be taken back to customers' wishes.