The communication methods employed by human dates back from a very early stages of civilization. In the primitive ages, communication were based on human voice. But it had a limitation, the distance. As distance grew between two people, messages got hard to convey due to the limitation of vocal cord. Next big step taken by human civilization was the invention of fire. He soon realized that this fire could be used for communication. During the attack in China, soldiers used to light up big smoke at regular intervals to warn others for impending attack. But the real development occurred in the fields of data communication was the development of Morse code by Samuel F.B.Morse. The code consists of basically on and off …show more content…
Light will reflect or refract with the surface depending on the angle at which strikes the surface. This principal is the heart of the operation of optical fibers. Just by altering and controlling the angle at which light is incident on the fiber, we can transmit this light signal efficiently. By this principle of Total Internal Reflection the ray of light is trapped within the denser glass of the center of the composite cylindrical glass fiber, the core as if it is guided down the core in a zigzag path of successive reflections. These light waves are guided through the core of the optical fiber just like a radio frequency signal in a coaxial …show more content…
If Ɵ1 is greater than the critical angle then light cannot refract across. The critical angle is the angle whose sin is n2/n1. (Davis)
The refractive index of the medium is a number that characterizes the optical density of the medium in vacuum. It means the change in the speed of light that travels through a medium relative to vacuum. When a ray of light strikes the boundary at an angle greater than the critical angle, it reflects back into the medium. It does not cross over to the next medium. (Davis)
What is Fibre Optics
Now what is Fibre Optics. They are long strands of pure glass , very thin, usually about the diameter of the hair which are bundles together. These bundles are called optical cables and this is used to transmit light signals over very long distance. If we take a single optical fibre and cut it, the cross sectional view will look something like the following picture. (Paschotta)
It consists of three main parts.
• Core- Thin glass center of the fibre through light