Optical Fibers

Optical fibers consists of thin stands of glass or glass like material which are so constructed that they carry light from a source at one end of the fiber to a detector at the other end.

The light sources used are either LEDs (stands for Light Emitting Diodes) or LDs (stands for Laser Diodes).

The data which are to be transmitted, firstly modulated onto the light beam using the frequency modulation techniques. The signals can then be picked up at the receiving end and then demodulated.

The bandwidth of the medium is potentially very high. For Light Emitting Diodes (LEDs), this ranges between 20Mbps and 150Mbps and higher rates are possible using Laser Diodes (LDs).

ISP uses fiber optic cable to join their networks.

The fiber optical cable consists of the following three pieces:

  • the core - the glass or plastic through which the light travels
  • the cladding - is a covering of the core that reflects light back to the core
  • protective coating - protects the fiber cable from hostile environment

Types of Optical Fiber Cable

There are two type of fiber optic cable that are described in the table given below:

Type Description
Single Node Supports a segment length of upto 2 kms and bandwidth of upto 100 Mbps
Multinode Supports a segment length of upto 100 kms and bandwidth of upto 2 Gbps

Advantages of Optical Fiber Cable

Here are the list of some main advantages of using the optical fiber cables:

  • Fiber optic is immune to electrical and magnetic interference i.e., noise in any form because the information is travelling on a modulated light beam
  • Fiber optic is highly suitable for harsh industrial environments
  • Fiber optic guarantees secure transmission and has a very high transmission capacity
  • Fiber optic cables can be used for broadband transmission where several channels i.e., bands of frequency, are handled in parallel and where it is also possible to mix the data transmission channels with channels for telescope, graphics, TV and sound

Disadvantages of Optical Fiber Cable

Below are list of some main disadvantages of using the optical fiber cables:

  • Installation problem because fiber optic cables are quite fragile and therefore may need special care to make them sufficiently robust for an office environment
  • Connecting either two fibers together or a light source to a fiber is a difficult process
  • Optical fibers are virtually impossible to tap only because of noise immunity. And in order to incept the signal, the fiber must be cut and a detector inserted
  • Light can reach the receiver out of phase
  • Connection losses are common problems in optical fiber cables
  • Fiber optic cables are more difficult to solder
  • Optical fiber cables are the most expensive cables among all the other cables

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