Transporting Light By Fibre Optic Refraction And Reflection
Light is refracted when it travels through transparent materials of different densities. The fibre optic cable's transparent core has a higher refractive index than the less dense transparent cladding that surrounds it. The angle of incidence or refraction in the less dense lower refractive index transparent material is always larger than the angle of incidence or refraction in the denser higher refractive index transparent material. The angle of incidence of the core is smaller than the angle of refraction of the cladding.
The difference in the refractive indices directs the sunlight through the cable by a process called total internal reflection. When the incident angle in the core equals the critical angle, the refracted light travels along the boundary between the two materials. When the angle of incidence in the core is greater than the critical angle all of the light is reflected and not refracted. The light travels by reflection through the fibre optic cable.
2 Light Traveling Through A Fibre