Question

Write difference between LED and Laser Diode.

Answer 1

LASERs (also known as laser diodes or LD) and LEDs (light emitting diode) have different characteristics in the way in which they emit light. While a LASER emits converged light, the output of an LED is highly diverged.
The spectral width of an LED is bigger than that of a LD. A bigger spectral width enables higher link bandwidth on the FOC. For an LED the spectral width is about 80 nm when it operates at 1310 nm and 40 nm at 850 nm. The spectral width of a LD is 3 nm for operation at 1310 nm and 1 nm at 850 nm.