OPTICAL FIBRE

Common

lwl Optical cables are transporting the signal with light pulses. They are made of polymer or glass the typical diameter is devided into 4 layers:

1. Core
2. Cladding
3. Coating or Buffer to protect the mantle
4. Jacket the outer shell

Advantages compared to copper cables

Optical cables are superior within almost all regards. They support ultra low diameters, low signal resistance and are not prone to electrical noise or EM field distortions.

Optical cables support data transfers over vast distances at high data rates featuring low weight and a very long service life.
Thanks to galvanic isolation renders grounding needless.
The reduced raw materials requirements saves the enviroment and reduces cost.

Disadvantages to copper cables

The main problem with optical cables is their mechanical properties. The optical fiber is more prone to damage than a copper cable and it can only be slightly bend or tilt. It can only be used on a relatively straight path. When installing another disadvantage comes to play: The jack is way more complicated to install to the cable, so most of the optical cables come ready to use.

Important special designs

Depending on the intended setup there are special optical wires available: Outdoor cables can be put into the ground or into pipes. They are moisture resistant and more rersistant in general compared to indoor cables. They even can withstand rodent bites. Breakout cable are multichannel cables, the consist of many individual cables. They split at the end and can be equipped with several different plugs. This way many cables can be installed in a minimum of time.

Simplex-Duplex cable (direction-dependent)

Optical cables are communication channels. These channels differ by their direction-dependency: Simplex is transfer into one direction while duplex stands for both directions at the same time. Simplex cables are outfittet with simplex-plugs, each fiber carries a data stream into one direction. The duplex cable supports at least two fibers (and a duplex plug) and therefore transport into more than one direction. Duplex cables are usually supplied with duplex plugs already attached.

Multimode/Singlemode/Monomode

One more feature with optical fibers is the size of the inner core. The core of Singlemode OS1 and OS2 is with 9 μ m so small that only one mode can be supported. A mode can be explained by a single light pulse within the cable.
In larger multimode fibers (OM1, 2, 3, 4) up to 62.5 μ m more than one mode can be established at the same time. The handling is less complicated, but the signal gets distorted with increasing distance. Multimode cables are installed in distances of less than 1 km.

Common plugs

Optical fiber cables support many different plugs. The following table presents you with the most common types.

Illustration	Name	Description
	Lucent Connector	The Lucent connector (LC) is known as standard LAN cabling from data centers. It is useable with single- and multimode. The compact design only requires very limited space in the rack cabinet. The automatic locking push/pull lock eases the setup.
	Subscriber Connector	The „Subscriber Connector“ (SC) is the predecessor of the LC plug. This plug is single- and multimode capable and equipped with push/pull lock.
	Straight Tip	The „Straight Tip“ (ST), or also known as „BOFC-Plug“ is the old standard for LAN cabling and still widely used. With it´s bayonet lock it is to be used for single- and multimode.
	MTRJ	The „MTRJ“ plug looks like a RJ45-Plug and supports high density and easy setup. It is single- and multimode capable.
	E2000	The compact plug „E2000“is the standard for WAN- and MAN cabling. It´s push-pull lock with integrated cap protects the plug from dust and the eyes of the operator from laser radiation.

Connections

Splicings

Splicings are plug free couplings between two fiber cables by using a arc splicer. The inner cores are combined precisely with each other. An outer protection protects the coupling.

Connectors

Plugs can be connected to a pigtail connector which is connected to another plug of an installation optical cable.

Optical cables in audio setups

LWL_Toslink At audio setups optical cables are used due to their superior resistance to noise and EM fields and high sound quality. The most common cables is the Toslink cable to be used with audio devices with SPDIF interface. Car manufacturers are going to use more and more of optical cabling to reduce weight and minimize fuel consumption.