Basic structure of optic fiber cable

Basic structure of optic fiber cable

                                               

An optical fiber can be called as a dielectric waveguide. This waveguide operates at optical frequencies.

The fiber consists of three parts namely

1.       Core

2.       Cladding and

3.       Buffer coating

The core of the fiber is cylindrical and has a radius a. its refractive index is represented by n1.

The core is surrounded by a solid dielectric cladding whose refractive index is n2. The refractive index of the core n1 is always greater than the refractive index of cladding n2. The cladding gives mechanical strength to the inner core.

The buffer coating gives additional strength and prevents any damage to the fiber.

Since the cladding that surrounds the core has lower refractive index than the core, the light is guided through the core due to total internal reflection.