What is optical fiber and what are its practical applications
Before talking about what fiber is, I imagine that the Romans must have been particularly pleased with themselves the day they invented lead pipes around 2000 years ago. Finally, they had an easy way to get their water from one place to another. Imagine what they would do with these cables - modern fiber optic "tubes" that can carry phone calls and emails around the world in a seventh of a second!
What is fiber optics?
We are used to the idea of information that travels in different ways. When we talk about a fixed telephone line, a wire cable carries the sounds of the voice in a socket on the wall, where another cable takes it to the local telephone exchange. Cell phones work in a different way: they send and receive information through invisible wireless waves, since they do not use cables. To answer our question, which is fiber optics, we have to know what works as a third way. The information encoded in a light beam is sent through a glass or plastic pipe. It was originally developed for endoscopes in the 1950s to help doctors see the inside of the human body without having to cut it or open it with a scalpel. In the 1960s, engineers found a way to use the same technology to transmit phone calls at the speed of light (186,000 miles or 300,000 km per second).
Optical technology
To understand what optical fiber is, we have to know that a fiber optic cable is made up of very thin filaments of glass or plastic known as optical fibers; A cable can have as few as two strands or as many as several hundred. Each cable internet companies strand is less than one-tenth the thickness of a human hair and can carry something like 25,000 phone calls, so a complete fiber optic cable can easily carry several million calls.
Fiber optic cables transport information between two places using fully optical (light-based) technology. Suppose you want to send information from your family computer to a friend's house on the street using fiber optics. The computer could be connected to a laser, which would convert the electrical information from the computer into a series of pulses of light. Then it will fire the laser through the fiber optic cable. After traveling on the cable, the beams of light would appear at the other end. Your friend would need a photoelectric cell (light detector component) to convert the pulses of backlight into electrical information that your computer could understand. So the whole device would be like a very advanced hi-tech version of the type of phone that can be made of two cans and a rope!
144-fiber fiber cable - which is fiber optic
Photo: A fiber optic cable of 144 strands. Each strand is optically pure glass and is thinner than a human hair.
What is fiber optics and how does it work?
In our dissertation of what optical fiber is, we have to talk about light traveling through a suitable cable, bouncing repeatedly against walls. Each of the small photons (light particles) jumps down the tube like a sled going down an ice rink. Now you could expect a beam of light, which travels in a transparent glass tube that can simply get out of the edges. But if the light strikes the glass at a very low angle (less than 42 degrees), it reflects back again, as if the glass were really a mirror. This phenomenon is called total internal reflection. It is one of the things that keeps the light inside the tube.
The other thing that prevents the light from coming out of the pipe is the structure of the cable, which is made up of two separate parts. The main part of the cable in the middle is called the core and that is the part through which the light travels. Wrapped around the outside of the core is another layer of glass called the coating. The work of the coating is to keep the light signals inside the core. You can do this because it is made of a different type of crystal. (More technically, the coating has a lower (refractive index).
