What does the term "core" refer to in fiber optics?

The term "core" in fiber optics specifically refers to the light-carrying part of the fiber. This central region of the fiber optic cable is designed to transmit light signals. The core is surrounded by a cladding layer, which has a lower refractive index than the core, allowing the light to be reflected back and propagate through the core, even when the fiber is curved or bent. The effectiveness of the transmission depends largely on the properties of this core, including its material, diameter, and refractive index.

Other options relate to different components or characteristics of fiber optic cables, but they do not define the core. For instance, the outer layer, often referred to as the jacket or protective layer, serves to shield the fiber from physical damage and environmental conditions and is separate from the core itself. The overall length refers to the physical measurement of the cable but is not related to the function of light transmission, while the strength of the signal pertains to the quality and integrity of the transmitted signal rather than the structural component itself. Thus, recognizing that the core is integral for the conduction of light in fiber optics is essential for understanding how these systems transmit data.