What is the main difference between attenuation and dispersion in fiber optics?

The distinction between attenuation and dispersion is fundamental in fiber optics. Attenuation refers to the loss of signal strength as light travels through the fiber. This loss can be attributed to factors such as absorption, scattering, and bending losses. It is quantified typically in decibels per kilometer (dB/km), indicating how much the signal diminishes over distance.

Dispersion, on the other hand, relates to the spreading of light pulses as they travel through the fiber. This phenomenon can cause overlap between pulses, particularly over long distances, leading to decreased signal integrity and potential difficulties in signal interpretation. Dispersion is primarily affected by the wavelength of the light and the characteristics of the fiber, including design and materials.

The correct answer captures these definitions accurately, clarifying that attenuation deals with the reduction of signal strength while dispersion concerns itself with how light pulses spread over time. Understanding this difference is crucial for fiber optic technicians, as both factors significantly affect the performance and reliability of fiber optic communication systems.