What is Optical Fiber Dispersion?
Dispersion is the spreading out of a light pulse in time as it propagates down the fiber. Dispersion in optical fiber includes model dispersion, material dispersion and waveguide dispersion. Each type is discussed in detail below. Model Dispersion in Multimode Fibers Multimode fibers can guide many different light modes since they have much larger core size. This is shown as the 1st illustration in the picture above. Each mode enters the fiber at a different angle and thus travels at different paths in the fiber. Since each mode ray travels a different distance as it propagates, the ray arrive at different times at the fiber output. So the light pulse spreads out in time which can cause signal overlapping so seriously that you cannot distinguish them any more. Model dispersion is not a problem in single mode fibers since there is only one mode that can travel in the fiber. Material Dispersion Material dispersion is the result of the finite linewidth of the light source and the dependen
