What is Optical Fiber - Definition, Principle, Work, Advantages, FAQs

Define optical fibers or definition of optical fibers or what are optical fibers? -

Optical fibre is a data transmission device that uses light pulses that travel down a long fibre, which is commonly constructed of plastic or glass. Metal wires are preferred for optical fibre communication transmission because signals travel with less harm. Electromagnetic interference has no effect on optical fibres. The total internal reflection of light is used in the fibre optical cable. Depending on the power and transmission distance requirements, the fibres are designed to aid in the propagation of light in conjunction with the optical fibre. Long-distance transmission is done using single-mode fibre, while shorter distances are done with multimode fibre. These fibres' outer wrapping need more protection than metal wires.

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1. Define optical fibers or definition of optical fibers or what are optical fibers? -
2. Principle of optical fibers-
3. Work of optical fiber-
4. Advantages of optical fiber communication-

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What is optical fiber cable? Or define optical fiber cable -

Within a plastic casing, a fiber-optic cable may contain a few to hundreds of optical fibers. They convey data information in the form of light and travel hundreds of miles quicker than typical electrical wires.

Principle of optical fibers-

An optical fiber is a long, thin thread of material that is usually shaped like a cylinder. It has a layer of exterior protective covering called cladding around its core, which is positioned in the center. The cladding and the core are constructed of various materials. Light moves very slowly through the core before being transmitted to the cladding. Furthermore, the cladding reflects light back to the core, and so on.

When light from the core contacts the cladding's border at an angle less than 90 degrees, it bounces back. Light does not escape in any way, and it only emerges from the fibre's end. Scratches on the cable's cladding generally result in damage. To protect the cladding from harm, a plastic coating similar to the buffer is placed. This buffered fibre is usually found in the jacket, which is a robust layer. As a result, the fibre performs well without causing any damage.

Types of optical fiber-

The refractive index, materials utilised, and mode of light propagation all influence the types of optical fibers available.

The following is the classification based on the refractive index:

1. Step Index Fibers have a single uniform index of refraction and are made up of a core and cladding.
2. Graded Index Fibers: As the radial distance from the fibre axis rises, the refractive index of the optical fibre falls.

The following is a categorization based on the materials used:

1. Plastic Optical Fibers: For light transmission, polymethylmethacrylate is employed as the core material.
2. Glass Fibers: It is made up of ultra-fine glass fibres.

The following is a classification based on the mode of light propagation:

1. Single-Mode Fibers: These fibres are used to transmit signals over vast distances.
2. Multimode Fibers: These fibres are used to transmit signals across short distances.

The core's refractive index and mode of propagation are used to create four different types of optic fibres:

1. Single-mode fibres with a step-index
2. Single-mode fibres with a graded-index
3. Multimode fibres step-index
4. Multimode fibres with a graded-index

Work of optical fiber-

Total internal reflection is used to operate the optical fibre. Light beams can transport a large quantity of data, but they travel in straight lines, which is an issue. So, unless we have a long straight wire with no bends, making use of this advantage will be time-consuming. Optical wires, on the other hand, bend all light rays inwards (using TIR). Light rays travel indefinitely, bouncing off the walls of optical fibres and transmitting data end to end. Although light signals degrade with time depending on the purity of the material employed, the loss is substantially lower than with metal cables.

A Fiber Optic Relay System is made up of the following components:

1. The Transmitter generates light signals and encodes them for transmission.
2. The Optical Fiber is the medium used to transfer light pulses (signal).
3. The Optical Receiver - This device receives and decodes sent light pulses (signals) to make them usable.
4. An optical regenerator is required for long-distance data transmission.

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Advantages of optical fiber communication-

1. Cost-effective and economical
2. Non-flammable and thin
3. Power usage is reduced.
4. Signal degradation is reduced.
5. Lightweight and flexible

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NCERT Physics Notes:

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