Optical fibre communication
The optical fibre system is used for carrying light from one point to the other. It consists of transmitting device, receiving device and fiber optic cable. Transmitting device converts electrical signal to light signal. Receiving device converts light signal to electrical signal. The fiber cable is made of plastic or glass material which is transparent and thin in size. It is used to carry light. LED and Laser diodes are used in the transmitter and receiver modules of fiber chain respectively.
This technology has revolutionized telecommunications and data transmission due to its high data carrying capacity, low signal loss and immunity to electromagnetic interference. These advantages of optical fiber communication have made it the backbone of modern telecommunications networks and the internet.
What is fiber optic cable ?
As shown fiber consists of core, cladding, coating, strength member and outer jacket. The core is the thin glass which is used for light transmission and reception. Light gets reflected due to cladding and hence it can be easily transported through the core. Coating and jacket helps cable from damage.
There are two types of fiber optic cables viz. single mode and multimode cable.
• Single mode cable : It is a single strand of glass fiber with 8.3 to 10 microns in diameter. It carries single mode and supports higher
bandwidth than multimode fiber. It offers higher transmission rate and upto 50 times more distance than multimode. It supports lowest order bound mode
which can propagate at wavelength of 1300 to 1320 nm. Single mode fiber is often used for inter-city telephone trunks and video applications.
• Multimode cable : It is made of glass fibers with 50 to 100 microns diameter. Multimode fiber offers higher bandwidth at greater speeds over medium
distances. Light waves typically wavelength of 850 or 1300 nm travel through the core. Multimode fiber is usually used for LANs and WANs.
Fiber optic cable characteristics
Following are the unique benefits or characteristics of fiber optic cable.
• It can accommodate data transfer much faster than copper wire versions such as coaxial and twisted pair cables.
• Data can be sent as pulses of light over threads of glass at Gbps.
• Lines are free of EM (Electromagnetic) interference and hence it is difficult to tap by hackers.
• Data can travel for miles without a signal degradation.
• These cables are more immune to environmental extremes. They can operate over large variation in temperature. Moreover they are not affected by corrosive liquids and gases.
• They are non conductors and hence there is no shock hazards as no current or voltage is associated with them.
• They are small in size and light in weight which makes installation easier.
• The cost of fiber optic cable is less compare to other cable based systems.
Benefits or advantages of fiber optic cable
Following are the benefits or advantages of Fiber optic cable:
➨The fiber can carry large amount of data due to larger bandwidth capacity.
Data can be transmitted at very high speed usually 1.6 TB/sec in the field.
Due to this fact, next generation internet will be based on light.
It is known as LiFi (i.e. Light Fidelity).
➨Fiber incur low loss to the signal usually 0.3 dB/Km.
Hence optical repeaters are not needed for long distances.
➨Though the initial installation cost is higher. It benefits for long run due to more benefits compare to
earlier coaxial based systems.
➨The fiber optic system is immune against EM interference and hence can be laid near the high frequency towers and
places where electro-magnetic radiation is a concern. Moreover it does not radiate any EM waves as it operates on light and hence will
not affect any nearby EM signal based systems such cellular, microwave, satellite etc.
➨It has higher electrical resistance and gence can operate safely near to high voltage lines and equipments.
➨It is light in weight and hence easy to install.
➨The optical fiber transmission power is very less. Moreover light carried by cables do not leak other than beginning and end of
the system. Hence it does not have any crosstalk effect between the optical cables.
➨It does not generate any spark. Due to this fact it finds applications in automobile industry also.
➨Unlike RF based systems which can be tapped and intruded by the intruder, fiber based communication
can not be tapped as light is transported within the cable itself. This enhances security for individuals as well as
business enterprises.
Drawbacks or disadvantages of Optical fibre
Following are the drawbacks or disadvantages of Optical fibre:
➨Cost: The initial installation cost is higher due to expensive optical
transmitter and receiver. Moreover it requires specific tools for maintenance and repair.
➨It is difficult to splice compare to wires usually at the starting and end joints.
Moreover interfacing tools and connectors are costly.
➨When the light comes in contact with imperfection during travel and optical power is higher,
it leads to destruction of fiber cable. This can be prevented using fiber fuse devices, which breaks the circuit to prevent
further damage.
➨Fiber optic system can not carry electrical power which is often requirement at terminal equipments/devices.
Conclusion : In summary, fiber optic cables offer superior performance in terms of speed, data capacity, and resistance to interference but may come with higher upfront costs and require specialized equipment and expertise for installation and maintenance. The choice between fiber optics and other types of cabling depends on the specific requirements of the application and budget constraints.