- A technology that uses glass(or plastic) threads(fibers) to transmit data.
- A fiber optic cable consists of a bundle of glass threads, each of which is capable of transmitting messages modulated on to light waves.
- Fiber optic cables mostly used in telephone companies.
How Fiber-Optics Work?
- Light travels down a fiber-optic cable by bouncing repeatedly off the walls.
- A beam of light is travelling in a clear glass, when it hits glass at a really shallow angle(less than 42 degrees), it reflects back in again.
- This phenomenon is called total internal reflection.
- It's one things that keeps light inside the pipe.
- The other thing that keeps light in the pipe is the structure of the cable, which is made up of two separate parts.
- One is the middle part called as Core through which light passes.
- Second is the wrapper around the outside of the core is another layer of glass called the Cladding.
- The cladding's job is to keep the light signals inside the core. It can do this because it is made of a different type of glass to the core.
Single-mode fiber
- This is a simplest type of optical fiber.
- It has a very thin core about 5-10 microns in a diameter.
- In a single mode fiber, all signals travel straight down the middle without bouncing off the edges.
- They can carry information upto a distance of 200kms. Eg: Cable TV, Internet, and telephone signals are generally single-mode fibers.
Multi-mode fiber
- Multi-mode fiber cable is 10 times bigger than single-mode fiber cable.
- This means light beams can travel through the core by following a variety of different paths.
- They can carry information to a distance of only 2kms.
Advantages
- Fiber optic cables have a much greater bandwidth than metal cables. This means they can carry more data.
- Fiber optic cables are much thinner and lighter than metal wires.
- Data can be transmitted digitally rather than analogically.
- Cables are expensive to install.
- They are more delicate and easily broken.
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