What is the primary role of a fiber optic cable's core?

The primary role of a fiber optic cable’s core is to transmit light signals. The core is the central part of the fiber optic cable where the light signals travel. It is made of glass or plastic with a high refractive index, which allows it to effectively guide and contain the light through the principle of total internal reflection. This is crucial for the performance of fiber optic communication systems, as the ability to transmit data as light over long distances is what makes fiber optics such an effective technology for high-speed internet and telecommunications.

The other options pertain to functions that are not the primary purpose of the core. For instance, while mechanical protection and insulation are important for the overall integrity of the fiber optic cable, these functions are primarily associated with the cable’s outer layers, such as the protective sheath or cladding. Additionally, the absorption of excess light is not a function of the core; rather, it is designed to minimize loss of signal during transmission. Thus, focusing on the core's role in transmitting light signals is essential for understanding its importance in fiber optic technology.