REASON : LED's data rates problem

Hi,guys
I want to ask question which shown below

"From the point of view of modulation bandwidth and intramodal dispersion, explain why an LED can not be used to achieve gigabit data rates in an optical fibre communication system."

I cant recall what my lecturer taught me.


Regards
Linspire

hah a..doing the assignment i see! Nice..I'm looking for the answer as well..check this out..

"For this reason LEDs are most often used with multimode fiber. LEDs are used in
lower-data-rate, shorter-distance multimode systems because of their inherent bandwidth
limitations and lower output power. The output spectrum of a typical LED is about 40 nm,
which limits its performance because of severe chromatic dispersion. "

http://spie.org/Documents/Publicatio...odule%2008.pdf

Shehan

Thank you, Shehan.
This information is useful.