Optical Communication

Introduction

Optical communication is a type of communication in which signals are carried to the remote end through light, instead of electric current. It mainly relies on optical fibres to carry those signals to their destination. The components of optical communication include a transmitter/receiver, modulator/demodulator, transparent channel and a light signal. 

They can be classified into two types – guided optical systems and unguided optical systems. In the guided optical systems, the beam emitted by the transmitter is spatially confined whereas, in the unguided optical systems, the beam emitted is spread in space. 

Optical Communication

1. Optical communication is a method of communication in which the signal is sent to the distant end by light rather than an electrical current.
2. Optical fibre communication systems utilise optical fibres to transmit data. Due to optical fibre’s significant benefits over electrical transmission, copper wire communications have mostly been phased out of the developed world’s key networks.
3. Over the 1970s, when low-loss optical fibre communication systems were developed, optical fibre communication systems have become one of the most widely used modes of communication.
4. The primary advantages of optical communication includes the large bandwidth of optical fibre, very little data or signal loss, increased transmission range, and the absence of electromagnetic interference. The disadvantages include the expensive cost of cable, transmitter/receiver, and other supporting equipment, as well as the knowledge necessary to install and join cables.
5. Fibre optic cable advantages and disadvantages depend on many factors like cost, efficiency etc. Let us now discuss the advantages and disadvantages of optical communication in detail.

Advantages of Optical Fibre Cable

• Bandwidth: The bandwidth of optical fibre cables is much larger than that of metal cables
• Low Power Loss: The optical fibre’s low power loss makes greater transmission lengths possible. In contrast to copper, the suggested maximum distance for copper is 100m, whereas the recommended distance for fibre is 2km
• Security: Tapping optical fibres is tricky. Emissions cannot be intercepted since they do not emit electromagnetic radiation. Due to the difficulty of physically tapping, fibre is the most secure media available for transmitting sensitive data
• Interference: Electromagnetic interference is not a problem with fibre optic lines. It may even be used in electrically loud areas without causing damage to the fibre
• Cost: Unlike copper, glass raw materials are abundant. This implies that glass may be manufactured at a lower price than copper 
• Magnitude: Compared to copper, a fibre optic cable has almost 4.5 times the capacity and a cross-sectional area that is 30 times smaller than a wire cable
• Weight: The weight of fibre optic cables is much less than that of metal wires making them easier to install. Additionally, they take up less space than cables of similar capacity
• Flexibility: An optical fibre’s tensile strength is higher than that of copper or steel fibres of the like diameter. It is more malleable, bends easily, and is resistant to the majority of corrosive elements making them vulnerable

Disadvantages of Optical Fibre Cable

1. Splicing is Difficult: Optical fibres are difficult to splice, and light is lost in the fibre owing to scattering. They have a constrained physical cable arc. If stretched too much, they can break.
2. Costly to install: Optical fibres are relatively expensive to install, and professionals are required to install them. They lack the tenacity of wires. Optical fibres often need specialised testing equipment.
3. Highly vulnerable: Fibre optic cable is tiny and compact, making it very susceptible to being cut or damaged during installation or building operations. Fibre optic lines provide very high-speed data transfer. Thus, when fibre optic cable is selected as the transmission medium, restoration, backup, and survival must be addressed.
4. Cannot Be Curved: The optical fibre transmission needs repetition at predetermined intervals. When twisted around curves with a radius of just a few millimetres, the fibres may be snapped or suffer transmission losses.

National Optical Fibre Network (NOFN)

1. Access through optical fibre cable is provided in all state capitals, district headquarters, and up to the block level.
2. The government intends to link all of the country’s 2,50,000 Gram Panchayats to NOFN. This will be accomplished by leveraging existing PSU fibres (BSNL, Railtel, and Power Grid) and laying more fibre to link to Gram Panchayats as per requirement.
3. The resulting dark fibre network will be illuminated by suitable technology, providing adequate bandwidth to Gram Panchayats. This network will be known as the National Optical Fibre Network (NOFN). As a result, the connectivity breach between Gram Panchayats and Blocks will cease to happen.
4. All Service Providers will have equal access to the NOFN. These service providers, which include telecommunications service providers (TSPs), internet service providers (ISPs), cable television operators, and content providers, may provide various services in remote locations.
5. These operators may offer a variety of applications, including e-health, e-education, and e-governance.
6. NOFN is anticipated to cost around Rs. 20,000 crore. The Universal Service Obligation Finance funds the project (USOF).

Conclusion 

Optical communication, also known as optical telecommunication, makes communication possible through light to carry the information. Modern-day communication depends on optical networking systems using optical fibres, lasers, and routers.