hi umar syed
dispersion ———–> technically speaking reffers to the variation of speed of wavelengths in a medium.,..
distortion….>technically speaking is DISPERSION and attenuation…
dispersions occurs becoz different wavelengths travel with different velocities in the fiber…
attenuation gennnerally for single mode fiber is 0.2dB/km… however this attenuation is also wavelength..
thus each wavelength travel with different velocity and attenuated with different magnitude leads to distortion
with regards