How Light Refraction Powers Fiber Optic Cables

Refraction, the bending of light as it transitions from one medium to another, occurs due to changes in the speed of light as it moves through different materials. Within a fiber optic cable, the core consists of a material with a high refractive index, while the cladding is made of a material with a lower refractive index. When a light signal enters the core of a fiber optic cable, it undergoes refraction, causing it to travel along the core. This happens because the higher refractive index of the core slows down the light.

When the light signal strikes the core-cladding boundary at a shallow angle, it experiences total internal reflection. This means that instead of refracting out into the cladding, the light signal bounces back into the core. This fundamental principle allows light signals to traverse significant distances without significant signal loss.

The total internal reflection of light is the linchpin for the efficient data transfer that fiber optic cables make possible. This mechanism ensures that the light signal remains confined within the core of the fiber, preventing it from escaping. This stands in stark contrast to traditional copper cables, where signal degradation occurs over distance.