What major factor contributes to a fiber optic cable's ability to support high bandwidths?

The ability of a fiber optic cable to support high bandwidths is significantly influenced by the mode of light propagation. Fiber optic cables can be categorized into two primary modes: single-mode and multi-mode. Single-mode fibers allow the transmission of light directly down the fiber core, resulting in minimal modal dispersion. This enables higher bandwidths over longer distances since there is less interference and signal loss.

In contrast, multi-mode fibers carry multiple light rays or modes with varying paths, which can lead to modal dispersion and limit bandwidth and distance. Therefore, the mode of light propagation is crucial for achieving high data transmission rates, making it the primary factor in a fiber's capacity to handle high bandwidth applications. While attributes such as the thickness of the cable, the number of fibers, and the length of the fibers can have roles in performance, they do not directly define the inherent capability of the fiber's bandwidth as the mode does.