All About Electronics: Advantages of optical fiber communication

All About Electronics: Advantages of optical fiber communication: Let us see the advantages of optical fiber communication over conventional communication system  Enormous bandwidth: the informati...

Advantages of optical fiber communication

Let us see the advantages of optical fiber communication over conventional communication system 

Enormous bandwidth: the information carrying capacity of a transmission system is directly proportional to the carrier frequency of the transmitted signals. The optical carrier frequency is in the range of 10^14Hz while the radio frequency is about 10^6Hz. Thus the optical fibers have enormous transmission bandwidth and high data rate. Using wavelength division multiplexing operation, the data rate or information carrying capacity of optical fibers is enhanced to many orders of magnitude.

Low transmission loss: due to the usage of ultra low loss fibers and the erbium doped silica fibers as optical amplifiers, one can achieve almost loss less transmission. Hence for long distance communication fibers of 0.002dB/km are used. Thus the repeater spacing is more than 100km. 

Immunity to cross talk: since optical fibers are dielectric wave guides, they are free from any electromagnetic interference (EMI) and radio frequency interference (RFI). Since optical interference among different fibers is not possible, cross talk is negligible even many fibers are cabled together. 

Electrical isolation: optical fibers are made from silica which is an electrical insulator. Therefore they do not pick up any electromagnetic wave of any high current lightening. It is also suitable in explosive environment.

Small size and weight: the size of the fiber ranges from 10 micrometers to 50 micrometers which is very small. The space occupied by the fiber cable is negligibly small compared to conventional electrical cables. Optical fibers are light in weight. These advantages make them to use in aircrafts and satellites more effectively.

Signal security: the transmitted signal through the fiver does not radiate. Unlike in copper cables, a transmitted signal cannot be drawn from a fiber without tampering it. Thus, the optical fiber communication provides 100% signal security. 

Ruggedness and flexibility: the fiber cable can be easily bent or twisted without damaging it. Further the fiber cables are superior than the copper cables in terms of handling. Installation, storage, transportation, maintenance, strength and durability.

Low cost and availability: since the fibers are made of silica which is available in abundance. Hence, there is no shortage of material and optical fibers offer the potential for low cost communication.

Reliability: the optical fibers are made from silicon glass which does not undergo any chemical reaction or corrosion. Its quality is not affected by external radiation. Further due to its negligible attenuation and dispersion, optical fiber communication has high reliability. All the above factors also tend to reduce the expenditure on its maintenance.

Basic structure of optic fiber cable

Basic structure of optic fiber cable

                                               

An optical fiber can be called as a dielectric waveguide. This waveguide operates at optical frequencies.

The fiber consists of three parts namely

1.       Core

2.       Cladding and

3.       Buffer coating

The core of the fiber is cylindrical and has a radius a. its refractive index is represented by n1.

The core is surrounded by a solid dielectric cladding whose refractive index is n2. The refractive index of the core n1 is always greater than the refractive index of cladding n2. The cladding gives mechanical strength to the inner core.

The buffer coating gives additional strength and prevents any damage to the fiber.

Since the cladding that surrounds the core has lower refractive index than the core, the light is guided through the core due to total internal reflection.