Which of the following best describes meridional rays?

The best description of meridional rays is that they consistently travel along the diameter of the fiber core. This characteristic is fundamental to understanding how light behaves within optical fibers. Meridional rays, by definition, strike the core at an angle of incidence that aligns with the diameter, allowing them to travel straight through the core without bouncing off the walls. This direct travel minimizes losses due to reflection and ensures effective transmission of light over long distances.

This concept is significant in optics and fiber technology because it contrasts with other types of rays, such as skew rays, which do not follow the diameter but instead travel at varying angles to the axis of the fiber. Understanding the behavior of meridional rays helps in designing systems that utilize optical fibers for communication and data transfer, optimizing their performance based on how light propagates through them.