In the designation 50/125 fiber, what does "125" refer to?

The designation "50/125 fiber" indicates a specific type of multimode optical fiber, where the "125" refers to the cladding size in microns. In this case, the fiber has a core diameter of 50 microns, which is the light-carrying portion of the fiber, and a cladding diameter of 125 microns, which surrounds the core. The cladding is crucial as it reflects light back into the core, ensuring that the light stays contained within it, thereby facilitating effective light transmission.

Understanding this designation is important for applications involving fiber optics because the core and cladding sizes determine the fiber's performance characteristics, such as its modal bandwidth and capacity to carry data over distances. The 125-micron cladding is a standard dimension for multimode fibers, making it essential for installations and compatibility with connectors and other fiber optic components.