Fiber optics is used to transmit television, voice, and digital data signals by light waves over flexible hair like threads of glass and plastic. It is evolved into a system of great importance and use since the 1980’s. Optical Fiber Communication System converts electrical signal which after passing through optical fiber cable is reconverted into electrical receiver
COMPOSITION OF OPTICAL FIBRES
- Silica based glass or plastics filaments are spun and packed into bundles of several hundreds or thousands. Bundles may be put together as rods or ribbons and sheets.
- These bundles are flexible and can be twisted and contorted to conduct light and images around corners.
- The thin glass centre of the fiber where the light travels is called the “core”.
- The outer optical materials surrounding the core that reflects the light back into the core is called the “cladding”.
OPERATION OF OPTICAL FIBER
- In a fiber optic system, there are a few major components to perform the task of communication.
- The Input Modulator is needed; this modulates the incoming signals with a light beam.
- A light emitting device is used; it can be either a LED or a semiconductor laser diode.
- A fiber optic cable is used as a transportation medium.
- A fiber optic converts an electrical signal to an infrared light signal, and then transmitted the signals onto an optical fiber.
TYPES OF OPTICAL CABLES
- STEP INDEX
This cable index of refraction is for the core and the cladding. It causes deformation due to the various paths length of the light ray. This is called modal distortion. It is the cheapest type of cabling. Within the cladding and the core, the refractive has a specific index is constant.
- GRADED INDEX
In this cable, rays of light follow sinusoidal paths. Although the paths. Although the paths are different lengths, they all reach the end of the fiber at a same time. Multimode dispersion is eliminated and pulse spreading is reduced. It can hold the same amount of energy as multimode fiber. The disadvantage is that this takes place at on one wave length.