Which of the following materials typically serves as the core of optical fibers?

The core of optical fibers is typically made from glass, which is essential for the transmission of light signals over long distances. Glass fibers have a high refractive index, allowing them to transmit light with minimal loss due to internal reflections. This property enables efficient data transfer and communication, making glass an ideal choice for optical fibers in telecommunications and networking applications.

While plastic can also be used to create optical fibers—specifically in less critical applications or for short-distance communications—glass is preferred for its superior performance characteristics, such as lower attenuation and greater bandwidth capabilities.

Copper and aluminum are not used as core materials for optical fibers; they are primarily used in coaxial or twisted pair cables for electrical transmission. The properties of glass fibers ensure effective light propagation, which is crucial for the performance of modern communication systems.