What is the difference between multi-mode and single-mode fiber?
Multimode fiber is generally used for fiber runs that are less then 2 km. Singlemode fiber is generally used for fiber runs greater than 2 km. The reason for this is that the inside diameter of the glass tube inside the cable is much smaller for singlemode fiber (8 or 9 micron) vs. multi-mode fiber (50 or 62.5 micron). The smaller the diameter, the less the light will bounce. This results in less optical loss and greater distance.
