What are the two main types of optical fibers?

The correct answer identifies the two primary classifications of optical fibers based on their mode of light propagation: single-mode and multi-mode fibers.

Single-mode fibers have a small core diameter and allow only one mode of light to propagate. This design minimizes modal dispersion, making single-mode fibers ideal for long-distance communication where high bandwidth and low attenuation are critical. The light travels straight down the fiber, resulting in lower signal loss over longer distances.

In contrast, multi-mode fibers have a larger core diameter, enabling multiple modes or paths of light to propagate simultaneously. This design is suitable for shorter distances, as the multiple paths can cause modal dispersion, leading to reduced bandwidth over longer runs. Multi-mode fibers are often used within data centers and for short-range applications.

While plastic and glass fibers are often discussed in the context of material composition, the significant distinction in performance and application lies in the mode of light propagation, which is why recognizing single-mode and multi-mode fibers is essential in understanding fiber optics technology. Other options, while they may describe different aspects of fiber optics, do not classify fibers in terms of their operational modes, which is fundamental for technicians working with optical networks.