Multimode fiber is much more sensitive to dispersion than single mode fiber because of its large core, as
shown in figure 5 different rays making up a bit of data take different paths as they propagate. These rays arrive at
the receiver at slightly different times resulting in the broadening of the optical pulse. To compensate for pulse
broadening the multimode fiber core has a graded refractive index profile shown in figure 11. The refractive index of
the fiber is greatest in the center of the core and decrease rapidly until it becomes constant near the core/cladding
interface. The refractive index value effects the speed of light, the greater the refractive index the slower light
propagates making the ray passing directly through the center of the core travel slower than rays near the outside.
Rays arrive at the receiver with less temporal distortion reducing the dispersion of the fiber.