In fiber optics, what does the term "total internal reflection" describe?

The term "total internal reflection" describes a phenomenon that allows light to be completely reflected within the fiber core. This occurs when light traveling within the fiber reaches the core-cladding interface at an angle greater than the critical angle, which results in the light being reflected back into the core instead of refracting out into the cladding. This principle is crucial for the operation of fiber optics, as it enables signals to be transmitted over long distances with minimal loss of light.

The effectiveness of total internal reflection depends on the difference in refractive indices between the core and the cladding materials. A higher refractive index in the core compared to the cladding ensures that most of the light remains confined within the core, facilitating efficient data transmission. Understanding this concept is essential for anyone working with fiber optics, as it underpins the technology that enables high-speed communication systems.