[Physics Class Notes] on Optical Fiber Pdf for Exam

Light pulses are transmitted from one end of an optical fiber to another on a flexible, transparent fiber made up of plastic or glass. A fiber optic network can provide high-speed and long-distance services.

Fiber optic cables are typically used in telecommunications services such as the Internet, telephone, and television.

Copper cables lack many of the advantages that fiber optic cables have. The cables transmit information far more quickly and have a higher bandwidth.

There are many glass components in an optical fiber, which may range from a few to as many as a few hundred. In this case, the fiber cable consists of a layer of glass called cladding enclosing the glass fiber core. In addition, the cladding is shielded by a tube known as a buffer tube. The jacket layer is the final protective layer present on the strand.

1. Core- It is a thin piece of glass located near the center of the fiber on which the light is transmitted

2. Cladding- A glass core surrounds a material on the outside called the outer material. During normal operation, the outer material reflects light back into the core.

3. Buffer Coating- Fibers are protected by a plastic coating that prevents damage from the elements.

How does an Optical Fiber work?

According to the total internal reflection principle, optical fibers work. There is a problem here – light rays travel in straight lines, which can make it difficult for them to carry large amounts of data. As a result, harnessing this advantage will be very difficult without a long straight wire without any bends. To overcome this distortion, optical cables are designed in such a way that all the light beams are bent inward (using TIR). Throughout the optical fibers, light rays bounce off the walls and transmit data from one end to the other. Over longer distances, lights do degrade, depending on the purity of the material, but they do so at a much lower rate than using metal cables. Fiber Optic Relay Systems are composed of the following components:

1. Transmitter-Light signals are produced and encoded in order to be transmitted.

2. Optical Fiber-Light pulses (signals) are transmitted through this medium.

3. Optical Receiver-The receiver receives the transmitted light pulses (signals) and decodes them into usable signals.

4. Optical Regenerator-Data transmission over long distances requires this.

The Types of Optical Fibers

Optical fibers come in various types based on their refractive indices, materials, and light propagation modes.

According to refractive index, the classification is as follows:

Step Index Fibers: They are characterized by a core covered with a cladding that has a uniform refractive index.

Graded Index Fibers: Increasing distances from the fiber axis cause the refractive index of the optical fiber to decrease.

As a result of the materials used, it can be classified as follows:

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

 

There are four types of optic fibers depending on their mode of propagation and refractive index, which are as follows:

• Step index-single mode fibers

• Graded index-Single mode fibers

• Step index-Multimode fibers

• Graded index-Multimode fibers